Teenage Kicks: New (Old) Evidence on the Pill and Teenage Childbearing
Kelly S. Ragan
Stockholm School of Economics March 4, 2015
Abstract
How did the introduction of oral contraception (‘the Pill’) alter teenage childbearing in Sweden? Teen fertility was halved in the decade following the Pill’s introduction.
New data on oral contraceptive sales reveals that the largest declines occurred in com- munities with high take-up of the Pill. Di¤erences-in-di¤erences-in-di¤erences (DDD) comparisons, exploiting time variation across localities and age groups, point to a strong negative relationship between Pill use and fertility. Illegitimacy patterns from a century earlier are used as instruments to isolate that part of Pill use which is predetermined. IV estimates imply that the Pill’s di¤usion could account for the entire decline in teenage childbearing observed in the data. The estimated e¤ect on non-marital childbearing is large and negative; the data do not support the predictions of Akerlof et al (1996) but are consistent with the female empowerment model of Chiappori and Orre…ce (2008).
JEL Codes:
Keywords: contraception, teenage childbearing, out-of-wedlock birth Preliminary and Incomplete
Address: Stockholm School of Economics, Box 6501, 113 83 Stockholm, Sweden. Kelly.Ragan@hhs.se.
This work was supported by the Swedish Science Council (Grant 2012-643) and by the Swedish Royal Acad- emy of Science. I appreciate helpful comments from seminar participants at the NBER Summer Institute and SOFI, Stockholm University.
1 Introduction
This article presents new Swedish data on the use of oral contraceptives (’the Pill’) and develops an empirical approach to isolate a causal channel between Pill use and teen fertility.
I establish a strong …rst stage relationship between illegitimacy in 1860 and Pill take-up a century later. I use these predetermined di¤erences in Pill adoption to isolate the causal e¤ect of the Pill on teenage childbearing. The identifying assumption behind my choice of instrument is consistent with the teen fertility data along many dimensions including placebo policy reforms, the time pattern of reduced form e¤ects, as well as overidenti…cation tests using alternative instruments. The Pill had a statistically and quantitatively signi…cant e¤ect on teenage childbearing that could explain the halving of the teen birth rate after the Pill was introduced. By identifying the e¤ect of Pill use on teen fertility this paper quanti…es an empirical relationship that previous reduced form estimates have not been able to characterize.
There are few more compelling examples of technology as liberator than the Pill. Yet, the literature is divided regarding its importance. Declines in fertility were underway well before the Pill was introduced.1 These long run trends, common across many countries, led Becker (1991) and others to conclude that the Pill may have only represented a shift along the technological frontier rather than a contraceptive innovation. Even if the Pill was an improvement relative to existing contraceptive methods, the theoretical literature is ambigu- ous regarding the Pill’s probable e¤ects on nonmarital childbearing. Akerlof, Yellen, and Katz (1996) provide a theoretical model of contraceptive innovation and female immisera- tion, and argue that the Pill could increase the rate of out-of-wedlock childbearing among young women.2 Chiappori and Ore¢ ce (2008) develop a matching model with an explicit role for contraception which clearly predicts that universal access to an inexpensive and highly e¤ective mode of contraception, such as the Pill, should reduce non-marital childbearing. My IV approach, unlike previous quasi-experiments, is not limited to shifting Pill take-up among either married or unmarried teens; hence I can decompose fertility e¤ects by marital status.
1A prominent study of the Swedish case can be found in Schultz (1985).
2Akerlof et al (1996) emphasize how the pill and liberalized abortion access altered ’shotgun marriage’
customs and reduced the bargaining power of women with preferences against contraception, inducing some to engage in premarital sex whom otherwise would not, a force leading to increased non-marital fertility.
Theory is ambiguous, but the data is clear. The Pill substantially reduced nonmarital child- bearing among teens in both absolute and relative terms. The data do not support Akerlof et al (1996), but are consistent with the predictions of Chiappori and Ore¢ ce (2008).
Goldin and Katz (2002) use legal reforms that altered contraceptive access for unmarried women between the ages of 18 and 21 as a source of exogenous variation in Pill use to estimate the e¤ect of Pill access on marital delay and career choice among young college educated women in the U.S. Much of the ’power of the Pill’literature has focused on early legal access to the Pill, not Pill use per se. Bailey (2010) uses the repeal of Comstock laws which banned contraceptive sales to estimate the e¤ect of Pill access on marital fertility.
Ananat and Hungerman (2012), Bailey (2006), and Bailey, Hershbein and Miller (2012) are prominent examples which use family planning policy and legal reforms that altered contraceptive access to estimate how Pill access a¤ected women and the well-being of their children. These studies generally …nd negative fertility e¤ects. Yet, recent work by Myers (2012) argues that once abortion access is taken into account, con…dential access to the Pill had little e¤ect on women’s propensity to marry or have a child at a young age. Focusing on teenagers does not resolve this ambiguity. Using a quasi-experimental design Guldi (2008)
…nds small negative fertility e¤ects of con…dential early access to the Pill among white teens but no e¤ect for other teenagers.3
This paper empirically establishes a negative causal relationship between Pill use and teen fertility in total, as well as among subpopulations of teens, using a new empirical strategy which does not rely on variation in contemporary legal reforms or family planning policy.
The Swedish institutional setting mitigates confounding factors such as abortion legalization emphasized by Myers (2012) and Joyce (2013).4 Concerns related to policy endogeneity in the quasi-experimental literature and potential bias when relying on legal reforms as a source of identi…cation are moot since the Pill was available to all women over the age of …fteen with no restrictions regarding marital status or parental consent. The instrumental variables approach I use relies on a very di¤erent source of variation in Pill take-up than any previous
3This is not inconsistent with the literature on teen pregnancy prevention interventions. DiCenso et al (2002) survey 22 randomized studies and present a meta-analysis of interventions to reduce teen pregnancy.
They …nd little e¤ect of these interventions on contraceptive use or pregnancy among teens.
4Abortion was illegal in Sweden until 1975.
study. The reduced form estimates I report point to a sizable fertility reduction among teens related to con…dential Pill access. Moreover, I estimate …rst stage equations that clearly establish the channel through which exogenous variation in Pill use operates, and complement reduced form analysis with a full model where the causal chain is made explicit.5
Decomposing fertility e¤ects by marital status not only allows us to discern which theory match the data but also presents new puzzles with respect to the role the Pill played in the secular declines in marital childbearing among teens observed in the data. Total teen fertility declines match up well with the di¤usion of the Pill. Consistent with Bailey (2010), I …nd that marital fertility among married teens declines signi…cantly. Yet, my estimates overstate declines in non-marital fertility and predict an increase in marital fertility, consistent with the positive correlation in the cross section data between the di¤usion of the Pill and marital fertility among teens. To better understand the observed and predicted increase in marital fertility with respect to Pill di¤usion I examine how the Pill altered marital behavior. My estimates suggest that the Pill increased marriage among teens, consistent with increased marital childbearing, but at odds with the marital delay mechanism emphasized in Goldin and Katz (2002).
The empirical approach developed here could be used to evaluate the impact of the Pill on a host of other behaviors. Establishing the impact of the Pill on fertility is a necessary …rst step before one can establish any causal relationship between the Pill and other downstream outcomes such as earnings or child outcomes. The paper proceeds with an overview of the introduction of the Pill in Sweden with particular attention to the data used in this study as well as important aspects of the institutional environment. A …rst look at the data on the Pill and teenage childbearing is then presented. Using variation across time, across localities, and across age groups with di¤erential take-up rates I establish a strong negative relationship between the Pill and teen fertility. Section 4 presents the empirical model and the identifying assumptions behind the instrumental variables (IV) approach. Section 5 makes a case for the instrument, showing how illegitimacy from 1860 is highly correlated with Pill use, but uncorrelated with changes in teen fertility before the Pill is introduced.
5Bailey, Hershbein and Miller (2012) provide evidence that early legal access increased pill use, but their main results, consistent with this literature focus on estimating the e¤ect of early legal access on behavioral outcomes. It should be noted that they do report …rst stage results for rural women.
Placebo policy estimates and intention to treat (ITT) e¤ects implied by the empirical model match up precisely with the timing of the Pill’s introduction. Section 6 presents the main empirical results on teenage childbearing, while Section 7 decomposes the e¤ect of the Pill with regard to marital status. Section 8 concludes.
2 The Introduction of the Pill in Sweden
The Pill was approved for contraceptive use by the Swedish Board of Health and Welfare in May of 1964. Pill use grew rapidly. Three percent of women between the ages of 15 and 44 were on the Pill in 1965, ten percent a year later, and by 1969 a quarter of fecund females were on the Pill.6 Only condoms and coitus interruptus surpassed the Pill as a means of preventing pregnancy among Swedish couples.7 By 1976, 30 percent of women in their reproductive years were using the Pill annually, and more than half of teenage girls were on the Pill by 1979.8 The unique data on Pill use and the institutional setting surrounding the Pill’s introduction and rapid adoption are described below.
2.1 Data on Pill Use
I quantify the speci…c channel of the Pill with data on oral contraceptive (OC) sales. Data on OC sales by locality are constructed from 1970 onward using the quarterly Swedish Drug Market publication from Läkemedelstatistik, AB. This publication presents complete infor- mation on OC sales across 70 local markets that constitute the entire universe of OC sales in Sweden. Although the Pill was introduced in 1964, local sales data is …rst available in 1970.
Previous studies have relied on retrospective surveys to determine whether and which types of contraceptives women used at di¤erent points in time. Individual level surveys are useful in eliciting information on which types of birth control methods women had experience with, but this information on the extensive margin is an incomplete picture of women’s exposure to the Pill. I take a di¤erent approach. I use actual sales data. Pill sales capture both the
6Swedish Board of Health and Welfare (1984).
7See Lewin (2000). There are no recurring surveys on contraceptive use during this period so it is not possible to see how pill use evolved relative to other contraceptives.
8See Table 2 of Swedish Board of Health and Welfare (1984).
extensive margin, more and more women opt to try the Pill, as well as the intensive margin that women continue to take the Pill. The direct quanti…cation of Pill use proximate to the Pill’s introduction is an important contribution of this study.
Pill use is quanti…ed in terms of expenditures per woman or teen. Geographically disag- gregated data does not distinguish between di¤erent types of OC and only reports sales in Swedish Krona (SEK). Converting sales into doses requires a price index, and the additional assumption that the composition of OC sales across communities is uniform. Converting sales data into doses introduces measurement error, to avoid this the main results are presented in terms of sales. Table 1 presents data on OC sales and price data on the most popular brand of OC by year. Price data can be used to transform sales into doses. For example, Follinyl was the most popular OC accounting for over 27 percent of sales in 1970. A 21 day regimen of Follinyl was priced at 2.94 SEK, less than the price of a movie ticket. Annual OC sales correspond to over 400,000 women using the leading brand annually. According to the leading brand price index, roughly a quarter of fecund females were using the Pill in 1970, consistent with the data reported by the Swedish Board of Health and Welfare (1984).
2.2 Swedish Institutional Setting
Use of the Pill was widespread, especially among young women. Swedish law provided women as young as 15 access to contraceptive services without regard to parental knowledge or consent. Maternal health clinics provided information about contraceptives and supplied di- aphragms to women regardless of their marital status, and had since the 1950s. The Riksför- bundet för Sexuell Upplysning (RFSU) kept a list of doctors known to provide contraceptives but by the late 1960s they deemed this unnecessary as doctors were universally willing to provide contraceptive services to women.9
The assumption of uniform institutions may be di¢ cult to support in some settings, but in the context of Sweden this assumption is accurate in both the de jure and de facto sense. The laws regulating the sales of contraceptives do not di¤er by jurisdiction and are set by national regulatory bodies. In addition, the medical and retail pharmaceutical sectors in Sweden are highly regulated, and almost entirely operated by public entities that are subject to central
9See Linner (1967).
administration.10 Prescription drugs could only be distributed by a publicly administrated network of pharmacies whose assortment of drugs, sta¢ ng, and hours of operation were subject to public supervision. Drug prices were …xed and did not vary across markets. In this unique setting where the supply curve for the Pill was ‡at, …xed and identical across markets, di¤erences in take-up are arguably demand driven. The importance of the demand side of the market in determining Pill use will inform the IV approach.
3 A First Look at the Data
Using data on OC sales as a prism to shed light on the fertility decisions of teenagers helps build the case that the Pill’s di¤usion played a causal role in the steep decline in teenage childbearing observed in Sweden. Pill use in Sweden was heavily skewed toward young women.
By the late 1970s more than half of teenaged girls were using the Pill. Given that such a large share of teens came to use the Pill it is natural to ask whether there is any evidence in the aggregate that the Pill altered fertility patterns among teenagers.
Time series and cross-section data illustrate how the introduction of the Pill coincided with a steep drop in teenage fertility that was largest in communities where take-up of the Pill was greatest. This analysis is combined with data on the fertility patterns of older women who used the Pill at much lower rates to construct a di¤erences-in-di¤erences-in-di¤erences (DDD) estimator of the Pill’s impact on teen childbearing. The descriptive statistics point to a strong negative relationship between the Pill and teen fertility.
3.1 Time Series Data on Teen Fertility
Figure 1 shows how teenage childbearing fell by nearly 2 births per 100 women, a 50 percent decline, in the decade following the Pill’s introduction.11 Teenage marital fertility essentially disappeared after the Pill, declining from 1.5 births per hundred teens in 1965 to less than 0.3 births in 1975. Non-marital fertility also declined.
10In addition to these features of the legal and medical environment, it should also be noted that sex education has been compulsory in Sweden since 1956, and that the guidelines for the sex education curriculum are set at the national level.
11Oral contraceptives were …rst approved for use in May of 1964.
Figure 1: Teenage Fertility 1961-1975
The distribution of teen fertility rates across markets is plotted in Figure 2. The sharp decline in teenage childbearing is re‡ected in the leftward shift in the distribution from 1965 to 1969. In 1965, 20 percent of teens lived in communities with three or fewer births per 100 teens. By 1969 80 percent of teens lived in communities with less than three births per 100 teens, and by 1973 almost all teens lived in areas with less than three births.
0.2.4.6.81Probability <= Birth Rate
0 2 4 6
Births Per 100 Women Aged 15-19
1961 1965 1969 1973
Note: Fertility per 100 women. Population weighted
Distribution of Teenage Fertility Rates
Figure 2: Distribution of Teen Fertility
-1-.50.51
0 5 10 15 20 25
Pill Use Per W oman 15-19
Log Differences Fitted values
-4-202
0 5 10 15 20 25
Pill Use Per W oman 15-19
Level Differences Fitted values
Note: Pill use measured in SEK per 15-19 year old women. Fertility is per 100 women ag ed 15-19.
10 Year Log (Left Panel) and Level (Rig ht Panel) Differences
Pre/Pos t Pill Change in Fertility vs . Pill Us e
Figure 3: Change in Teen Fertility vs. Pill Use
3.2 Time Variation Across Communities: Di¤erences-in-Di¤erences
Fertility declines were not uniform, but occurred to a larger extent in communities with high take-up of the Pill. Figure 3 plots 10 year changes in teen fertility from before until after the Pill against Pill use by market.12 Although teen births fell in most communities, declines were largest where take-up of the Pill was greatest. Time di¤erences net out …xed factors across markets. The negative slope in Figure 3 indicates that permanent fertility di¤erences do not explain the negative relationship between teen fertility and Pill use.
3.3 Time Variation Across Communities and Age Groups: Di¤erences- in-Di¤erences-in-Di¤erences
Time variation across communities and age groups can be used to construct a di¤erences- in-di¤erences-in-di¤erences (DDD) comparison. Table 2 uses data on the age distribution of
12Log di¤erences in the left panel, level di¤erences in the right panel. The sizes of the circles in Figure 3 indicate market population.
-1-.50.51
Log Differences
0 5 10 15 20 25
-.8-.6-.4-.20.2
0 2 4 6 8 10
-1.5-1-.50.5
0 2 4 6 8 10
-4-202
Level Differences
0 5 10 15 20 25
Pill Per Woman Aged 15-19
-6-4-202
0 2 4 6 8 10
Pill Per Woman Aged 30-34
-4-3-2-101
0 2 4 6 8 10
Pill Per Woman Aged 35-39 Note: Fertility expressed per 100 women of each age group.
10 Year Changes
Pre/Post Pill Differences i n Fertili ty vs. Pi ll Use By Age
Figure 4: Di¤erences in Fertility from Before and After the Pill vs. Pill Use by Age Pill prescriptions to compare the fertility of low/high Pill use age groups in low/high Pill use markets before and after the introduction of the Pill.13 I use data on the age distribution of Pill use to de…ne a high use age group, women aged 15-19, and two low use age groups, women between 35-39 and 30-34. Figure 4 presents 10 year log di¤erences (top panel) and level di¤erences (bottom panel) in births per 100 women by age before/after the Pill relative to Pill expenditures. The negative correlation between fertility changes and Pill take-up seen among teens is reversed among older women where relatively high Pill use communities have smaller fertility declines.
Comparing fertility patterns of women who use the Pill at much lower rates than teens allows us to account for the role of location speci…c trends in driving teen fertility changes.
Table 2 presents the data as a DDD comparison. Average changes in births before/after the Pill in both low and high Pill use areas (de…ned as above or below median Pill use per
13Women between 30 and 34 accounted for 12 percent of scripts for the pill and women aged 35-39 together accounted for 9 percent of pill sales. According to the Drug Information Committee of the Swedish Board of Health and Welfare (1984) a quarter of OC prescriptions were written to teenagers. This is more than double the share of prescriptions written to women in their early thirties, and three times that of women in their late thirties. (insert: relative to their population shares.)
woman 15-44) for high Pill use teens and low Pill use populations are presented. Di¤erencing between high and low Pill use areas approximates the slopes for each age group plotted in Figure 4. Di¤erencing again across age groups gives an estimate of the total e¤ect of the Pill, net of both age and community speci…c time e¤ects. Dividing through by di¤erences in average Pill use across groups we have an estimate of the coe¢ cient on Pill use in a linear fertility model that includes both age and community speci…c time e¤ects. The DDD analysis suggests that community speci…c trends, such as a general decline in fertility in urban areas, cannot explain the strong negative association between Pill take-up and teen fertility seen in Figure 3.
3.4 Looking at the Data: A Summary
A negative relationship between the di¤usion of the Pill and teenage childbearing is seen in the data. The steep decline in teen fertility that coincides with the introduction of the Pill and the strong negative relationship between fertility declines and Pill use are reinforced by the DDD analysis which nets out the e¤ect of market level trends. The strong negative relationship holds regardless of whether fertility changes are measured in log or level di¤erences. The negative relationship is robust to the inclusion of age and community time e¤ects, but there remain a host of confounding factors that could explain the negative association seen in the data. For example, trends in local marriage markets speci…c to teenage girls may drive fertility changes, not the Pill.14 In the next section I write down a model that allows for unobserved location speci…c time e¤ects in teen fertility and outline an IV approach aimed at identifying the causal e¤ect of the Pill by identifying a part of Pill use that is predetermined by historical factors from a century earlier and arguably unrelated to contemporaneous trends in labor and marriage markets.
4 The Empirical Model
Consider a model where teen fertility in community i and time t, denoted Birthi;t, is a function of Pill use in community i, a community speci…c …xed characteristic, i, teen speci…c
14More generally, the concern is that there are omitted fertility trends speci…c to teens by each location.
local time e¤ects, denoted by i;t, and an idiosycratic fertility shock denoted by "i;t: Birthi;t = P illi;t 1+ i+ i;t+ "i;t:
Rewrite the model in di¤erences that span the introduction of the Pill:
Birthi;t Birthi;t j = P illi;;t 1+ i;t i;t j + "i;t "i;t j:
Initial Pill use is zero everywhere and hence omitted. The persistent community character- istic, i, is di¤erenced out.
The challenge is to estimate when the local trends in fertility related to other factors, captured by the i;t’s, are unobserved. This is addressed by using an instrumental variables approach, where out-of-wedlock births (OWB) from a century earlier are used to instrument for the di¤usion of the Pill. The instrument for Pill use is de…ned the following way:
Zi;t = 8<
:
0 t < 1964 OW Bi t 1964
Time variation comes from the legalization of the Pill, common across communities. Cross section variation in latent demand comes from historical illegitimacy patterns. The inter- action of the Pill’s legalization and historical patterns that determine latent demand de…ne the instrument, Zi;t = OW Bi I(1if t 1964, else 0):
Illegitimacy from a century earlier is highly correlated with take-up of the Pill, as shown in the next section. I make the additional assumption that historical illegitimacy is uncorrelated with contemporaneous fertility trends across communities, except through the in‡uence on Pill use. This means Zit Zit j is uncorrelated with both i;t i;t j and "i;t "i;t j, or
cov( i;t i;t j; Zit) = 0:
In words, this choice of instruments assumes that changes in teen motherhood during the late 1960s are not a¤ected by the level of illegitimacy from a century earlier except through the take-up of the Pill.
By using historical variation in illegitimacy I isolate that part of Pill use which is pre- determined. The strong relationship between illegitimacy in 1860 and Pill use provides a
channel through which exogenous di¤erences in Pill demand can be identi…ed. The empiri- cal model explicitly takes into account the direct e¤ect that persistent factors may have on teenage fertility across communities through i. This provides some plausibility to the ex- clusion restriction. Although the identifying assumption cannot be veri…ed, the next section will show how illegitimacy in 1860 is uncorrelated with trends in teen fertility in the period prior to the Pill’s legalization, consistent with the identifying assumption that underlies the empirical model.
5 Historical Illegitimacy and the Pill
Since the 17th Century, large and persistent di¤erences in out-of-wedlock births (OWB) divided Sweden into distinct demographic regions.15 OWB patterns are interesting not only as a demographic regularity invariant to mass migration and industrialization, but also as a strong predictor of latent demand for the Pill.16 Illegitimacy rates from 1860 predict a quarter of the variation in Pill use a century later. This section documents the correlation between Pill take-up and OWB in 1860, paying particular attention to how OWB is related to fertility trends before and after the Pill’s introduction.
5.1 The Geography of Historical Illegitimacy and Pill Use
Sundbärg (1910) compiled data through the 17th Century to illustrate how di¤erences in illegitimacy behavior persisted over hundreds of years. A single characteristic that de…nes illegitimacy patterns is di¢ cult to discern; high rates of illegitimacy are seen north and south of the limes norrlandicus, along coasts and plains. Mining and industrial regions have relatively high occurrence of unwed birth, but many areas with high levels of illegitimacy were primarily agrarian. Heckscher (1949) argued that urbanization led to the di¤erential pattern of out-of-wedlock fertility, but Frykman (1975) shows how areas with high illegitimacy had population densities no di¤erent from central Småland, an area of low illegitimacy.
15See Sundbärg (1910).
16Frykman (1975) presents a detailed analysis of non-marital fertility trends and the ethnological back- ground regarding their social roots. Sklar (1977) also discusses the importance legal and economic develop- ments in the 19th century with regard to illegitimacy in Sweden.
Figure 5: Maps of Out-of-Wedlock Births in 1860 and Pill Use per Woman in 1970
Figure 5 maps illegitimate births per 100 live births across markets in 1860 and demand for the Pill a century later. These maps illustrate the positive correlation that underlies the strong …rst stage result presented in the next section. The maps illustrate how the correla- tion between unwed births and Pill use a century later is not solely driven by North/South di¤erences. Even within regions, illegitimacy and Pill use are closely related. Similarly, urban- ization does not seem to be the de…ning factor driving illegitimacy and Pill take-up. Although Stockholm has the highest rates of Pill use and illegitimacy, Gothenburg, the second largest city, is not one of the top ten Pill demand markets nor is it an area of high illegitimacy in 1860.
5.2 Illegitimacy in 1860 and Teen Fertility: Before the Pill
If teen speci…c time e¤ects are correlated with OWB in 1860 this would violate the identifying assumption. I can’t test this directly, but I can test whether changes in teen fertility before the Pill are correlated with OWB in 1860. Table 3 summarizes results from regressions of changes in teen fertility on historical illegitimacy, year …xed e¤ects, and regional time trends.
The top panel uses measures of teen fertility in logs and levels, the middle panel looks at younger and older teens, and the bottom panel breaks out teen fertility by marital status.
There is no signi…cant correlation between fertility changes before the Pill and OWB in 1860 regardless of the measure used. The lack of a signi…cant correlation between teen fertility before the Pill’s introduction and illegitimacy from a century earlier is reassuring, as it is consistent with the identifying assumption behind the IV model.
5.3 Illegitimacy in 1860 and Teen Fertility: Placebo Treatments
Placebo experiments are another way to test whether OWB in 1860 is correlated with local time e¤ects before the Pill. I de…ne a placebo instrument identical to the instrument de…ned in Section 4 except for the timing of the Pill’s introduction:
Zi;t62= 8<
:
0 t < 1962 OW Bi t 1962
Speci…cation 1 in Table 4 reports the intention to treat (ITT) coe¢ cients on OWB in 1860 for a …xed e¤ects regression on a panel of teen fertility from 1961-1963. The coe¢ cient on the placebo instrument is not signi…cantly di¤erent from zero. The second speci…cation extends the data window by one year, conducting the same placebo treatment. Speci…cation 3 estimates the e¤ect of a placebo treatment corresponding to the Pill being introduced in 1963. The coe¢ cients are not signi…cantly di¤erent from zero.17 Placebo tests provide further reassurance that the instrument is not correlated with trends in fertility before the Pill’s introduction.
5.4 Illegitimacy in 1860 and Teen Fertility: The Reduced Form
The Pill’s legalization in 1964 should induce fertility responses well before disaggregated sales data become available in 1970.18 I test whether the instrument is working through the hypothesized channel, legal access to the Pill, by estimating a reduced form model in the period following legalization. The model estimated in Table 5 parallels the model in Section 4 where P illi;t has been replaced with the instrument Zi;t.19 Table 5 reports the coe¢ cients on OWB in 1860 as the data window is extended from 1965 through 1974. The coe¢ cient estimates reported in Table 5 suggest that the Pill had a negative and signi…cant e¤ect on fertility, corresponding to a drop of almost 17 percent in the decade after the Pill was approved for contraceptive use.20 Reduced form estimates provide further support for the identifying assumption, namely that legalization of the Pill in 1964 drives the importance of OWB in 1860 as a predictor of teen fertility declines, not trends coinciding with data availability in 1970.
A similar reduced form approach can be used to trace out how the Pill altered teen fertility at speci…c points in time relative to the pre-legalization period. Figure 6 plots ITT
17The results are the same when placebo tests are run on speci…cations in levels.
18See Section 2.1 for further details on the data.
19The equation estimated in Table 5 is Birthi;t = Zi;t 1+ i+ t+ jt + "i;t where Zi;t is de…ned as
Zi;t = 0 t < 1964 OW Bi t 1964
and j denotes region speci…c time trends. Robust standard errors are clustered at the market level. All of the ITT estimates reported in Table 5 are weighted by the teen population.
20The total e¤ect is computed by multiplying b by the population weighted average value of OWB in 1860
e¤ects and con…dence bands from rolling one year response estimates. The …rst two points correspond to the placebo estimates reported in speci…cations 1 and 3 of Table 4 scaled by the teen population weighted illegitimacy rate in 1860. The vertical line indicates the introduction of the Pill. There is an immediate reduction in teen fertility of almost 7 percent in 1965, a year of partial treatment, relative to the pre-legalization period. The e¤ect grows rapidly through 1969 when the estimated reduction reaches 27 percent. The estimated e¤ects gradually decline during the 1970s, reaching 15 percent in 1974. The estimated magnitudes of the ITT estimates mirror the dynamics of aggregate Pill use reported by the Swedish Board of Health (1984). The share of women aged 15-44 using the Pill on an annual basis is plotted by the dashed line, and illustrates a rapid take up of the Pill that peaks in the late 1960s and then declines gradually through 1974. The reduced form estimates capture the increasing intensity of treatment and subsequent decline observed in the aggregate data.
Reduced Form Fertility E¤ect Estimates and the Share of Women Using the Pill by Year
Teen fertility is strongly predicted by OWB in 1860 in the years following the Pill’s in- troduction, but not in the years immediately preceding legalization. Reduced form estimates from placebo treatments and the actual legalization of the Pill make a strong case for the instrument shifting Pill take-up, and in turn fertility, while being uncorrelated with contem- poraneous fertility trends. The timing corresponds precisely to the introduction of the Pill, matching the relative magnitudes of the time pattern of initial partial treatment as well as the data on the Pill’s di¤usion in the aggregate.
6 The Pill’s Impact on Teenage Childbearing
The reduced form estimates discussed in the previous section not only make a strong case for the instrument working through the hypothesized channel but also suggest that con…dential access to the Pill reduced teenage childbearing for the average teen by 17 percent in the decade following the Pill’s approval for contraceptive use.21 With data on Pill use across markets we can take the analysis a step further, characterizing the relationship between Pill use, not just Pill access, and teen fertility. By estimating the full model presented in Section 4 we can quantify the causal channel between Pill use and teen fertility.
Table 6 present OLS and IV estimates of the Pill’s e¤ect on teen fertility based on a log linear version of the empirical model presented in Section 4, while Table 7 reports results for a linear in levels version of the model.22 Coe¢ cient estimates on Pill use are negative and highly signi…cant regardless of whether the results are weighted by the population of teen women (Tables 6 and 7 columns 1-2) or whether region trends are included.23 Speci…cation 2 in Table 6 includes both population weights and region trends, and is the baseline speci…cation used throughout the paper. OLS estimates of this baseline speci…cation (Table 6, column 2, top panel) suggest that every Krona increase in average Pill use reduced teen fertility by 2.4 percent.
IV estimates are roughly twice the magnitude of OLS estimates (second panel, Tables 6 and 7). The IV coe¢ cient from the baseline log linear model, dIVlog = 0:053, implies a predicted fertility decline of 69 percent if all teens behaved like the marginal teen identi…ed by the IV estimates, somewhat greater than the observed decline.24 The coe¢ cient from the comparable regression in levels, dIVlevel = 0:109, implies a predicted fertility decline of 1.42 births per 100 teens, less than the actual decline seen in Figure 1. Both OLS and IV
21See Table 5 for the ITT estimates and predicted fertility e¤ects. Since treatment intensities vary we can compute an interval of fertility responses ranging from a reduction of 6 percent in the community with the lowest illegitimacy in 1860 to a 40 percent reduction in Stockholm, the highest historical illegitimacy community.
22The equations estimated in Tables 6 and 7 are Birthi;t= P illi;t 1+ i+ t+ jt + "i;t where j denotes region speci…c time trends. Robust standard errors are clustered at the market level.
23Regions are de…ned as in Sundbärg (1910).
24See Table 6, column 2, middle panel. The bottom panel of Table 6 reports the …rst stage of the IV regression. Coe¢ cient estimates on historical illegitimacy are highly signi…cant, and the F-statistics reported in the middle panel are well above standard thresholds for weak instruments.
estimates point to a signi…cant negative relationship between Pill use and the teen birth rate.
First-stage results are reported in the bottom panel of Tables 6, and OWB in 1860 is highly signi…cant in all …rst stage regressions.
These results provide further evidence that the strong negative relationship between Pill use and teen fertility is causal. The larger magnitude of IV estimates, relative to OLS, may be driven by several factors. Attenuation bias, introduced by measurement error in teen Pill use, may contribute to the di¤erence in magnitudes between the estimates. Larger IV estimates may also be related to the instrument shifting the behavior of a highly responsive teen population. Predicted fertility responses based on the IV estimates are larger than the reduced form estimates in Table 5 and Figure 6. This is consistent with the fertility reduction for the marginal Pill user being greater than the fertility e¤ect of Pill access for the average teen. The IV coe¢ cients provide a consistent estimate of the fertility reduction among teenage Pill users and suggest that the Pill was a signi…cant contraceptive innovation for Swedish teens.
6.1 Alternative Instruments
Other historical instruments plausibly satisfy the exclusion restriction as well. Table 8 presents …rst and second stage results for alternative historical instruments.25 The …rst col- umn of Table 8 presents the baseline results using OWB in 1860, as reported in column 2 of Table 6. This speci…cation includes regional trends and is weighted by the teen population.
The second speci…cation presents results when nonmarital fertility is measured in 1910. The
…rst stage is strong and the coe¢ cient on Pill use is negative and highly signi…cant regardless of when OWB is measured. Speci…cations 3 and 4 use butter prices from the 19th Century to instrument for Pill take-up. The use of butter prices follows Schultz (1985) who showed how terms of trade shocks a¤ecting the dairy sector, the primary employer of women in 19th Century Sweden, altered women’s wages and in turn their marital fertility decisions. Butter prices provide a very di¤erent source of variation in Pill take-up that arguably satis…es the identifying assumption. The …rst stage is strong when using butter prices alone, or in combi-
25Note that regional time trends are included in all of the speci…cations in Table 8. Results are similar when region trends are excluded.
nation with OWB in 1860. Speci…cation 4 reports overidenti…cation test results (J-statistic).
The test does not reject the null hypothesis that the instruments are uncorrelated with the residuals from the estimation equation. This provides another piece of evidence consistent with the exclusion restriction.
6.2 Alternative Age Groups
My focus on teen fertility parallels Guldi (2008). Yet, much of the previous literature has focused on 18-21 year old women. Although age speci…c Pill use measures do not exist, I can measure fertility for these subpopulations before and after the Pill. Table 9 presents results from OLS and IV regressions of fertility among 15-17 year old women, 18-19 year olds, 18-21 year olds, and 15-21 year old women on teen Pill use, year and market …xed e¤ects, region trends, and population weights. Point estimates are largest for the youngest age group, but generally similar to the baseline results in Table 6. IV estimates are twice the magnitude of OLS estimates across all age groups. Reduced form estimates, reported in the lower panel of Table 9, are highly signi…cant. For the case of 15-21 year old women, the predicted fertility reduction from Pill access is over 12 percent. This is larger than estimates reported in Guldi (2008) who found that con…dential access to the Pill reduced fertility for a similar population by 8.5 percent.
In addition to quantifying the fertility e¤ects of Pill access, I can also compute the pre- dicted fertility decline associated with using the Pill. For 15-21 year old women the OLS coe¢ cient is -0.017; instrumenting yields a coe¢ cient of -0.036.26 Given average Pill ex- penditures, this implies a predicted fertility reduction of 22 to 47 percent. The estimated fertility responses to Pill use are much greater than reduced form estimates. This suggests that reduced form estimates of the fertility e¤ects of con…dential access for the average teen signi…cantly understate the behavioral e¤ects of Pill use relative to OLS and IV estimates.
26Both coe¢ cients are signi…cant at the 0.1 percent level.
6.3 Robustness Checks
6.3.1 Alternative Clustering
One may be concerned that shocks are correlated across geographically proximate markets.
One way to take this into account is to cluster at a more aggregated level to allow for correlation of residuals across markets. Standard errors are little changed when clustering at the county level instead of the more disaggregated market level.
6.3.2 Alternative Pill Use Measures To be written.
6.4 Estimate Comparisons
The previous literature on the Pill has relied on reduced form estimation based on natural experiments which shifted access to the Pill for di¤erent populations at di¤erent points in time. Guldi (2008) focuses on teenagers con…dential access to the Pill. As seen in Table 5 and Figure 6, reduced form estimates of the impact of Pill access on teen fertility are generally larger for the Swedish case.
The main contribution of this paper, though, is to estimate the impact of Pill use on teen fertility. Although reduced form estimates such as Guldi (2008) and Bailey (2010), for the case of married teens, are suggestive of Pill use fertility e¤ects the causal channel is not well understood. Bailey, Hershbein and Miller (2012) report …rst stage results for rural women using changes in family planning policy as an instrument to shift Pill use, but their full model estimation is the exception in this literature. By making a case for historical illegitimacy as a valid instrument for Pill take-up, I can quantify the causal channel between Pill use and teen fertility in the wake of the Pill’s introduction, a relationship that relatively little is known about. The predicted fertility reduction associated with Pill use is 69 percent in the baseline speci…cation (Table 6, column 2). This suggests that reduced form estimates understate the fertility e¤ects of the Pill for the marginal Pill user identi…ed by IV.
Are the estimates reported in Tables 6-9 comparable to previous research on Pill use among Swedish teens? The Pill’s in‡uence on teenage childbearing in Sweden has been
studied by Grönqvist (2009). He uses the introduction of subsidies on teenagers purchases of certain types of OC in a subset of Swedish municipalities beginning in 1989, 25 years after the Pill’s introduction. Grönqvist (2009) estimates the e¤ect of exposure to a subsidy on the log teen fertility rate, the dependent variable in the baseline speci…cation and extensions presented here. Grönqvist estimates a coe¢ cient of -0.076 with a standard error of 0.054, and concludes that exposure to OC subsidies reduced teen fertility by 7.5 percent. The subsidy exposure e¤ect is not directly comparable to the ITT or full model estimates I present. One way to compare the fertility e¤ects induced by the Pill’s introduction to the subsidies considered by Grönqvist is to compute the implied subsidy rate that would have led to a fertility reduction similar to those predicted by the baseline estimates reported in Table 6. Grönqvist (2009) reports an average subsidy of 75 percent. Assuming linearity, a 10 percentage point increase in the subsidy rate translated into a one percent reduction in teen fertility. In comparison, the IV estimates in Table 6 (column 2) imply that con…dential access to the Pill, although unsubsidized, led to a 69 percent reduction in teen fertility. To generate a similar behavioral response using subsidies would require a subsidy rate of nearly 700 percent. Even in comparison to the ITT estimates reported in Table 5 and Figure 6, the subsidy exposure e¤ects reported by Grönqvist (2009) are a half or a third the size of estimates based on the Pill’s introduction. The behavioral responses brought about by the introduction of the Pill are larger than those brought about by later subsidy policies.
7 Marital and Nonmarital Childbearing and the Pill
Theory has focused on how contraceptive innovations alter nonmarital childbearing. Figure 7 plots log di¤erences before/after the Pill for both marital and nonmarital childbearing versus Pill use. The strong negative relationship between total fertility and Pill use is mirrored in the nonmarital fertility patterns plotted in the right panel. Yet, marital childbearing behaves very di¤erently; marital births per teen and Pill use appear to be positively correlated, as seen in the left panel of Figure 7. Did the Pill both increased marital fertility and reduce nonmarital fertility among teens? In the following sections I report estimates of the Pill’s e¤ect on childbearing among teenagers by marital status and relate these estimates to the
-4-3-2-10
0 5 10 15 20 25
Pill Use per Woman 15-19
Change in Marital Births Fitted values
-.50.511.5
0 5 10 15 20 25
Pill Use per Woman 15-19
Change in Nonmarital Births Fitted values
Note: Fertility is measured by mother's marital status but expressed per 100 of the total teen female population.
10 Year Log Differences Before and After the Pill
Change in Fertility vs. Pill Use by Marital Status
Figure 6: Changes in Teen Fertility by Marital Status
theoretical and empirical literature. In order to understand the forces that drive the fertility patterns seen in Figure 7 an analysis of teenage marriage behavior is also presented.
7.1 Nonmarital Childbearing
Akerlof et al (1996) emphasize how the di¤usion of improved contraceptives and the use of abortion may contribute to increased nonmarital childbearing as norms enforcing marriage in the case of pregnancy are eroded. Column 1 report results for a regression of the log of nonmarital births per single teens on Pill use, year and market …xed e¤ects, and regional time trends. Column 2 reports results for a similar model where nonmarital fertility is expressed per the total teen population. Estimates by OLS and IV are large, negative and highly signi…cant regardless of how nonmarital fertility is measured. Given average Pill use in 1974, the OLS estimates imply that nonmarital fertility dropped by 48 to 50 percent as a result of the Pill’s di¤usion. IV estimates are even larger.
The Pill may have led to a decline in nonmarital fertility relative to the teen population, but the share of nonmarital births among teens may have increased. In 1964, 59 percent of teen births occurred outside of marriage. By 1974 this rate had increased to 87 percent.
Swedish time series data is consistent with Akerlof et al (1996) in the sense that the OWB
share increased after the Pill was introduced. Yet, a positive correlation between the share of births occurring outside of marriage and the Pill is not seen in the panel regressions presented in Table 10 (column 3). Regressing the share of teen births that occur outside of marriage on Pill use per teen, year and market …xed e¤ects, and regional time trends yields a negative and signi…cant coe¢ cient on Pill use. The di¤usion of the Pill led to a decline in nonmarital fertility both relative to the teen population and as a fraction of teen births. Although a general increase in the non-marital fertility share coincided with the introduction of the Pill there is little evidence to support the view that the di¤usion of the Pill led to increased nonmarital fertility.
7.2 Marital Childbearing
Table 11 estimates the impact of the Pill on births per the married teen population in both logs (column 1) and levels (column 3). Column 1 reports OLS (top panel) and IV (bottom panel) estimates of the Pill’s impact on log births per married woman. The IV estimates,
dIV
log = 0:022 suggest that a one SEK increase in average Pill use translated into an decline in teen marital fertility of 2.2 percent. Given average expenditures of 13 SEK this translates into a marital fertility reduction of 29 percent. Column 3 reports estimates of a similar speci…cation where marital fertility is measured in levels. The IV estimate in column 3,
dIV
level = 1:681 implies that every Krona increase in average Pill use led to a decline of 1.68 births per 100 married women. This implies a reduction of 22 births per 100 married teens, half of the 1964 level.
The signi…cant and large negative relationship between marital fertility per the population of married women is consistent with the …ndings of Bailey (2010), though larger in both absolute and relative terms than the reduced form e¤ects she estimates. Bailey (2010) focuses on marital fertility relative to the population of married women, using sales bans as a way to identify the marital fertility e¤ects of Pill access. Bailey estimates the impact of sales bans for every year from 1951 through 1980. The largest fertility e¤ect among teenagers occurs in 1964, with sales ban states having almost one more birth per 100 married teens than states without sales bans. Marital births per married teen were very similar in the U.S.
and Sweden during this period. In 1963 there were 49 live births per 100 married teens in
the U.S. Hence, percentage increases in teen marital fertility induced by sales bans were on the order of 2 percent in 1964, an order of magnitude less than the estimated e¤ect of Pill use reported in column 1 of Table 11.
Having established that the Pill led to fewer births per married teen, and that the mag- nitude of this e¤ect was large, we turn the e¤ect of the Pill on marital fertility per the total teen population. If the share of teens that marry is inelastic to contraceptive innovations, or if the Pill led to a decline in the share of teens entering marriage, we would expect the share of marital births per the teen population to decline. A negative relationship is not born out in the data. Instead, we …nd a positive correlation between Pill use and marital births, as seen in Figure 7.27This positive correlation stands in sharp contrast to the negative relationship between Pill use and both total and nonmarital teen fertility. Estimating the impact of the Pill on marital births per the population of married teens misses the larger trend toward increased marital fertility brought about by increased entry into marriage, an e¤ect undocumented in the previous literature and discussed in the next section.
The Pill increased fertility within marriage among Swedish teens. This e¤ect is seen in columns 2 and 4 of Table 11 where the impact of the Pill on marital births per the total teen population is estimated. IV estimates of the log speci…cation, reported in the bottom panel of column 2, suggest that for every Krona increase in average Pill use marital births per the teen population increased by 5.5 percent. Column 3 reports estimates for a speci…cation in levels, and the IV estimates in the bottom panel point to a similar relationship where a one Krona increase in Pill use increased marital fertility by over 0.03 births per 100 teens, or an increase in marital fertility per teen of 29 percent relative to 1964 levels. The steady decline in marital childbearing per teen seen in the time series data does not appear to be driven by the di¤usion of the Pill. The next section presents evidence on how the Pill altered teen marriage behavior and contrasts these result to studies such as Goldin and Katz (2002) which have emphasized how the Pill led to marital delay among college educated women in the U.S.
27The positive relationship between Pill use and teen marital fertility is not mechanically driven by a decline teen marriage rates, as both marital and nonmarital birth rates are measured relative to the total teen population in Figure 7.
-.06-.04-.020.02
0 5 10 15 20 25
Pill per Woman 15-19
Women 15-19 Fitted values
-.3-.2-.10.1
0 5 10 15 20
Pill per Woman 20-24
Women 20-24 Fitted values
-.01-.0050.005
0 5 10 15 20 25
Pill per Woman 15-19
Women 15-17 Fitted values
-.15-.1-.050.05
0 5 10 15 20 25
Pill per Woman 15-19
Women 18-19 Fitted values
Note: Proportio n m arrie d is the rati o of m arrie d women to al l wom en i n each age group.
Change in Proportion Married vs. Pill Use
Figure 7: Female Married Population by Age
7.3 Teen Marriage and the Pill
Marriage among teens was on the rise in Sweden from 1960 when 2.7 percent of women aged 15-19 were married through 1968 when 5.8 percent married. Marriage rates declined sharply thereafter, only 2.5 percent of teens were married in 1969 and 1.3 percent by 1975. Despite this aggregate decline, Figure 7 depicts a weak positive relationship between Pill take-up and teenage marriage. Figure 7 plots log di¤erences in the share of married females relative to Pill use for several age groups. The top panel contrasts teen marital behavior to that of women aged 20-24, a population that more closely parallels the college graduates studied by Goldin and Katz (2002). Teen marriage appears to be positively related to Pill use, while marriage among women in their 20s shows a negative relationship. The bottom panel decomposes teen marriage for younger and older teens; a positive correlation is seen among both populations.
Although a thorough treatment of the Pill’s e¤ect on marriage is beyond the scope of the current study, the empirical model in Section 4 can be used to estimate the impact of the Pill on teen marriage. Table 12 reports results from OLS and IV regressions of the share of
teens that are married on current and lagged Pill use, as well as year and market …xed e¤ects and region time trends.28 OLS and IV estimates of the Pill’s e¤ect on marriage are reported for both women and men. For women, both OLS and IV results point to a positive and signi…cant relationship between adoption of the Pill and the decision to marry during their teens. The results are similar for men, though not signi…cant when estimated by OLS. The estimates in Table 12 suggest that a one SEK increase in Pill use among teens led to a 10 percent increase in the teen marriage rate. Goldin and Katz (2002) emphasize how the Pill enabled young college educated women in the U.S. to delay marriage. Although the Pill may have been important for fertility delay among women in their 20s, or women who completed a college degree, I do not …nd evidence that the Pill contributed to marital delay among Swedish teenagers in the decade after the Pill. To the contrary, the Pill appears to have increased teenagers likelihood to marry, and in turn increased marital birth among teens.
8 Conclusion
This paper investigates teenage childbearing in Sweden and estimates how Pill use altered fertility in the decade after its introduction. A novel IV strategy is presented which uses variation in nonmarital childbearing from a century earlier to identify exogenous variation in take-up of the Pill. IV estimates provide evidence that the di¤usion of the Pill led to a statistically and economically signi…cant reduction in teenage childbearing of 50 percent or greater. The fertility e¤ect of Pill access for the average teen substantially understates the impact of the Pill for the marginal Pill user identi…ed by the IV estimates. By identifying the e¤ect of Pill use on teen fertility this paper quanti…es an empirical relationship that the reduced form literature has not been able to characterize.
Full model estimates are di¢ cult to compare directly to the previous literature as most studies have reported reduced form estimates of the impact of Pill access. For example, Guldi (2008) estimates that Pill access reduced fertility for 15-21 year old women by 8.5 percent.
Table 9 presents reduced form estimates of the e¤ect of Pill access on births for a similar population which implies that Pill access reduced fertility by over 12 percent. Although
28Fertility results use lagged pill use, but it could be argued that current pill use is the relevant variable for marriage decisions.
the reduced form estimates I present in Section 5.4 are larger than many in the previous literature, their striking feature is how small the implied behavioral e¤ects are relative to the full model estimates discussed in Section 6.
Theory is ambiguous as to how women’s use of highly e¤ective contraceptive methods such as the Pill changed the composition of fertility across marital groups. The data is clear; the di¤usion of the Pill led to a decline in nonmarital fertility both relative to the teen population and as a fraction of teen births. The data do not support Akerlof et al (1996), but instead the female empowerment model of Chiappori and Orre…ce (2008).
I …nd evidence that the Pill reduced marital fertility among married teens. Point estimates are an order of magnitude larger than the estimates reported in Bailey (2010). Yet, the negative fertility e¤ects of the Pill among married teens does not translate into a decline in marital fertility in the aggregate. To the contrary, I estimate that marital fertility per the total teenage population increased in Pill use. Increased selection into marriage among young women is the driving force behind this rise in marital fertility. This facet of teen fertility has not been discussed in the previous literature and provides a point of comparison to the marital delay mechanisms emphasized by Goldin and Katz (2002) in their study of college educated women in the U.S.
Although the Pill may have in‡uenced a variety of decisions over women’s life course, its primary e¤ect must be seen with regard to fertility. In the absence of a measureable fertility response, ancillary e¤ects on marriage, education and income become tenuous. Using the introduction of the Pill in Sweden to estimate the e¤ect of Pill use on teen fertility and documenting a large and signi…cant e¤ect with regard to delay of fertility during the teenage years is an important contribution to the literature. Moreover, this paper presents an empirical design which opens the door to future studies regarding the long run impact of the Pill on women’s schooling, career choices, and child outcomes.
References
[1] Akerlof, G., J. Yellen, and M. Katz (1996), "An Analysis of Out-of-Wedlock Childbearing in the United States." The Quarterly Journal of Economics, 111(2): 277-317.
[2] Ananat, E. and D. Hungerman (2012), "The Power of the Pill for the Next Generation:
Oral Contraception’s E¤ects on Fertility, Abortion, and Maternal and Child Character- istics." The Review of Economics and Statistics. 94(1):37-51.
[3] Bailey, Martha J. (2006) “More Power to the Pill: The Impact of Contraceptive Freedom on Women’s Life Cycle Labor Supply.”The Quarterly Journal of Economics, 121(1):289–
320.
[4] Bailey, Martha J. (2010), ""Momma’s Got the Pill": How Anthony Comstock and Griswold v. Connecticut Shaped US Childbearing." American Economic Review, 100(1):
98–129.
[5] Bailey, Martha J. (2013), "Fifty Years of Family Planning: New Evidence on the Long- Run E¤ects of Increasing Access to Contraception." Brookings Papers on Economic Activity, ():341-395.
[6] Bailey, M., Hershbein, B. and A. Miller (2012), "The Opt-In Revolution? Contraception and the Gender Gap in Wages." American Economic Journal: Applied Economics, 4(3):
225-254.
[7] Becker, G. (1991), A Treatise on the Family, Harvard University Press, Cambridge.
[8] Chiappori, P. A., and S. Ore¢ ce (2008), "Birth Control and Female Empowerment: An Equilibrium Analysis." Journal of Political Economy, 116(1).
[9] DiCenso A., G. Guyatt, A. Willan, and L. Gri¢ th (2002). "Interventions to Reduce Un- intended Pregnancies among Adolescents: Systematic Review of Randomized Controlled Trials." British Medical Journal 324:1426-34.
[10] Frykman, J. (1975) "Sexual Intercourse and Social Norms: A Study of Illegitimate Births in Sweden 1831-1933." Ethnologia Scandinavica, 1975: 110-150.
[11] Frykman, J. (1977) Horan i Bonde Samhället. LiborLäromedel, Lund.
[12] Goldin, C. and L. Katz (2002), "The Power of the Pill: Oral Contraceptives and Women’s Career and Marriage Decisions."Journal of Political Economy,110(4):730-770.
[13] Grönqvist, Hans (2009), "Putting teenagers on the Pill: the consequences of subsidized contraception." Institute for Labor Market Policy Evaluation Working Paper No. 2009:8.
[14] Guldi, M. (2008), "Fertility E¤ects of Abortion and Birth Control Pill Access for Mi- nors." Demography, 45(4):817-827.
[15] Heckscher, Eli (1949), Sveriges Ekonomiska Historia Från Gustav Vasa: Andra Delen Det Moderna Sveriges Grundlägning Fösta Halvbandet. Albert Bonniers, Stockholm.
[16] Joyce, T. (2013), "If Only Policy Analysis Were So Easy." Journal of Policy Analysis and Management, 32(4):897-99.
[17] Lewin, Bo (2000), Sex in Sweden : on the Swedish sexual life 1996. Stockholm : National Institute of Public Health.
[18] Liljeström, Rita (1974), A Study of Abortion in Sweden: A Contribution to the United Nations World Population Conference. Royal Ministry of Foreign A¤airs. Stockholm:
Norstedt.
[19] Linner, Birgitta (1967), Sex and Society in Sweden. New York: Pantheon Books.
[20] Läkemedelstatistik, A.B. "Swedish Drug Market: Statistical Survey of Registered Phar- maceutical Specialties in Sweden." Stockholm. 1970(I)-1974(IV).
[21] Myers, C. K. (2012), "Power of the pill or power of abortion? Re-examining the e¤ects of young women’s access to reproductive control." IZA Discussion Paper No. 6661. Bonn, Germany: Institute for the Study of Labor.
[22] Schultz, T. Paul (1985), "Changing World Prices, Women’s Wages, and the Fertility Transition: Sweden, 1860-1910." Journal of Political Economy, 93(6): 1126-1154.
[23] Statistics Central Byrån (1864), "Befolkning Statistisk Årsbok 1860." SOS, Stockholm.
[24] Statistics Central Byrån (1904), "Befolkning Statistisk Årsbok 1900." SOS, Stockholm.
[25] Statistics Central Byrån (1914), "Befolkning Statistisk Årsbok 1910." SOS, Stockholm.
[26] Sundbärg, Gustav (1907), Bevölkerungsstatistik Schwedens 1750-1900. Reprinted in Ur- val 3, Statistika Central Byrån.
[27] Sundbärg, Gustav (1910), Emigrationsutredningen Bilaga V: Ekonomisk-statistisk beskrifning öfver Sveriges olika landsdelar. Royal Publisher, P. A. Norstedt and Sons, Stockholm.
[28] Swedish Board of Health and Welfare (1984), "Oral Contraceptives." National Board of Health and Welfare Workshop, Drug Information Committee, 1984:3, Stockholm.
Table 1: Pill Sales in Detail Annual Sale and Dosage
Year Total OC Sales Annual Doses Female Population OC Use
1000 SEK Woman Years Aged 15-44 Percent of Women
1970 14,948 423,452 1,585,915 26.7
1971 13,785 391,270 1,590,503 24.6
1972 14,697 374,973 1,591,942 23.6
1973 12,986 329,548 1,592,887 20.7
1974 14,079 334,983 1,600,290 20.9
Leading Brand Price Index
Year Leading Introduced Share of Price per
Brand OC Sales Month
1970 Follinyl 1968 Q4 27.3 2.94
1971 Follinyl 1968 Q4 33.0 2.94
1972 Follinyl 1968 Q4 36.9 3.27
1973 Follinett 1971 Q3 25.6 3.28
1974 Follinett 1971 Q3 31.9 3.50
Note: Price based on Q4 prices and sales data. Follinyl and Follinett produced by Recip.
Table 2: A Di¤erences-in-Di¤erences-in-Di¤erences Analysis Log Di¤erences in Births Before-After the Pill
Low Pill Use Area High Pill Use Area Di¤erence
Low Pill Users (30-34) -0.26 -0.21 0.04
(0.14) (0.13)
Low Pill Users (35-39) -0.49 -0.45 0.04
(0.22) (0.18)
High Pill Users (15-19) -0.21 -0.26 -0.05
(0.27) (0.26)
Di¤erence (Teens-30-34) 0.05 -0.05 -0.09
Slope of Log Fertility in Pill Use per Woman (Age 30-34 Control Group): -0.04
Di¤erence (Teens-35-39) 0.28 0.19 -0.10
Slope of Log Fertility in Pill Use per Woman (Age 35-39 Control Group): -0.04 Level Di¤erences in Births Before-After the Pill
Low Pill Use Areas High Pill Use Area Di¤erence
Low Pill Users (30-34) -2.10 -1.75 0.36
(1.16) (1.04)
Low Pill Users (35-39) -1.76 -1.49 0.27
(0.76) (0.57)
High Pill Users (15-19) -0.69 -0.80 -0.10
(0.87) (0.81)
Di¤erence (Teens-30-34) 1.41 0.95 -0.46
Slope of Log Fertility in Pill Use per Woman (Age 30-34 Control Group): -0.20
Di¤erence (Teens-35-39) 1.06 0.69 -0.37
Slope of Log Fertility in Pill Use per Woman (Age 35-39 Control Group): -0.16 Note: Births are measured per 100 women aged 15-19.
