Quarterly journal of economics
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1990].
11 Prior to the legalization of abortion, there was a very strong link between the number of unwanted births and low maternal education over the period from 1965 through 1970 [Commission on Population Growth and the American Future 1972, p. 98]. Levine et al. [1996] found that the drop in births associated with abortion legalization was not uniform across all groups. They estimated that the drop in births was roughly twice as great for teenage and nonwhite mothers as it was for the nonteen, white population. 12 In the years immediately following Roe v. Wade, data from the Centers for Disease Control [1994] indicate that almost one-third of abortions were performed on teenagers. An- grist and Evans [1996] found that while abortion reforms had relatively modest effects on the fertility of white women, “black women who were exposed to abortion reforms experienced large reductions in teen fertility and teen out-of-wedlock fertility.” A number of studies have shown that the availability of abortion improves infant outcomes by reducing the number of low birthweight babies and neonatal mortality [Grossman and Jaco- bowitz 1981; Corman and Grossman 1985; Joyce 1987; Grossman and Joyce 1990]. Moreover, Gruber, Levine, and Staiger [1999, p. 265] conclude that “the average living circumstances of cohorts born immediately after abortion became legalized improved sub- stantially relative to preceding cohorts.” They go on to note that “the marginal children who were not born as a result of abortion legalization would have systematically been born into less favor- able circumstances if the pregnancies had not been terminated: they would have been 60 percent more likely to live in a single- parent household, 50 percent more likely to live in poverty, 45 percent more likely to be in a household collecting welfare, and 40 percent more likely to die during the rst year of life.” Previous research has found that an adverse family environ- ment is strongly linked to future criminality. Both Loeber and 11. The high concentration rates of crime among a relatively small number of offenders makes it more likely that legalized abortion would have larger effects on crime than on other social outcomes such as high school dropout rates or unem- ployment rates. A given child who has failed to complete school or secure a job counts as only one event in measuring school dropout or unemployment rates. Conversely, a single child may commit hundreds of crimes and thereby contribute far more powerfully to a higher crime rate. 12. This is not surprising since in the late 1960s the “pill” and other birth control mechanisms were far more readily available to married, educated, and af uent women [Goldin and Katz 2000]. 387
LEGALIZED ABORTION AND CRIME Stouthamer-Loeber [1986] and Sampson and Laub [1993] present evidence that a variety of unfavorable parental behaviors (e.g., maternal rejection, erratic/harsh behavior on the part of parents, lack of parental supervision) are among the best predictors of juvenile delinquency. Raine, Brennan, and Medick [1994], and Raine et al. [1996] argue that birth complications combined with early maternal rejection predispose boys to violent crime at age eighteen. Rasanen et al. [1999] nd that the risk of violent crime for Finnish males born in 1966 is a function of (in descending order of impact): mother’s low education, teenage mother, single- parent family, mother did not want pregnancy, and mother smoked during pregnancy. It is possible that abortion could re- duce the number of children born under all these circumstances: teenagers who have abortions can get more education before they give birth and may delay childbearing until they are married or want a child or both. In addition, women who inadvertently become pregnant may have engaged in behavior such as smoking, drinking, or using drugs that elevate the prospect of future crim- inality of their offspring. A number of studies have looked at cases of women, living in jurisdictions in which governmental approval to have an abortion was required, who sought to have an abortion, but were denied the right to do so [David et al. 1988; Posner 1992, p. 283]. 13 Dagg [1991] reports that these women overwhelmingly kept their ba- bies, rather than giving them up for adoption, but that they often resented the unwanted children and were far less likely than other mothers to nurture, hold, and breastfeed these children. In an array of studies in Eastern Europe and Scandinavia, Dagg found that the children who were born because their mothers were denied an abortion were substantially more likely to be involved in crime and have poorer life prospects, even when controlling for the income, age, education, and health of the mother. This literature provides strong evidence that unwanted children are likely to be disproportionately involved in criminal activity, which may be the causal pathway from greater avail- ability of abortion to lower rates of crime. Evidence from prisoner surveys further reinforces the link between a dif cult home environment as a child and later crim- 13. David et al. [1988] review the ndings of separate studies of the effects of denied abortion for cohorts born in Goteberg, Sweden in 1939–1942, Stockholm in 1948, all of Sweden in 1960, and Prague in 1961–1963. 388
inality [Beck et al. 1993]. In 1991, 14 percent of prisoners re- ported growing up with neither parent present, and 43 percent reported having only one parent (compared with 3 percent and 24 percent, respectively, for the overall population). Thirty-eight percent of prisoners report that their parents or guardians abused alcohol or drugs; almost one-third of female inmates re- port being sexually abused before the age of eighteen.
Before presenting our empirical estimates in the next sec- tion, we present “back-of-the-envelope” estimates of the plausible magnitude of the impact of legalized abortion on crime. Previous researchers have studied (1) how legalized abortion affects birth rates across different groups, and (2) crime rates across groups. By combining these two sets of estimates, we can obtain a crude prediction of the impact of legalized abortion on crime. This analysis considers four factors: race, teenage mother- hood, unmarried motherhood, and unwantedness. Beginning with the rst three of these factors, we use the 1990 Census to determine the proportion of children in each of the eight possible demographic categories (e.g., white children born to teenage mothers growing up in a single-parent household, or black chil- dren born to nonteenage mothers growing up in two-parent households). We then use the estimates of Levine et al. [1996] to determine what those proportions might have been in the absence of legalized abortion. Using Rasanen et al. [1999] and observed frequencies of crime by race in the United States, we generate category-speci c crime rates corresponding to each of the eight cells. Combining these crime rates with the change in the number of births in each category due to abortion provides an estimate of the hypothetical reduction in crime. Finally, under the assump- tion that 75 percent of unwanted births are aborted (this number appears consistent with data from self-reported pregnancy histo- ries), we estimate the contribution to lower crime from fewer unwanted births. 14 It is important to note that our calculations below isolate the marginal contribution of race, teenage mother- hood, unmarried motherhood, and unwantedness. Thus, when 14. A full description of the assumptions and calculations is available from the authors on request. 389
computing the impact of race, we net out any racial differences in those other characteristics in order to avoid double counting. The results of this exercise for homicide are as follows. All values reported are the hypothetical reduction in total homicides committed by members of a given cohort. Through a purely me- chanical relationship, the 5.4 percent overall postlegalization de- cline in cohort size obtained by Levine et al. [1996] translates into a 5.4 percent reduction in homicide. Fertility declines for black women are three times greater than for whites (12 percent compared with 4 percent). Given that homicide rates of black youths are roughly nine times higher than those of white youths, racial differences in the fertility effects of abortion are likely to translate into greater homicide reductions. Under the assumption that those black and white births elimi- nated by legalized abortion would have experienced the average criminal propensities of their respective races, then the predicted reduction in homicide is 8.9 percent. In other words, taking into account differential abortion rates by race raises the predicted impact of abortion legalization on homicide from 5.4 percent to 8.9 percent. 15 Teenagers and unwed women experience reductions in fer- tility of 13 and 7 percent, respectively, well above that for non- teenage, married women. Rasanen et al. [1999] nd, after con- trolling for other characteristics, that having a teenage mother roughly doubles a child’s propensity to commit crime, as does growing up with a single parent. 16 Accounting for these two factors raises the estimated impact of abortion on homicide from 8.9 percent to 12.5 percent. Adjusting for unwantedness, which more than doubles an individual’s likelihood of crime based on the estimates of Rasanen et al. [1999], raises the estimates from 12.5 percent to 18.5 per- cent. The impact of unwantedness is large because abortion rates of unwanted pregnancies are very high, whereas wanted preg- nancies are by de nition not aborted. Thus, using past estimates in the literature, we crudely estimate that crime should fall by 18.5 percent in cohorts that 15. For other crimes, the impact of race is much lower because rates of offending and victimization are much more similar across races. 16. Comanor and Phillips [1999], using the National Longitudinal Survey of Youth, nd that adolescents in households with absent fathers are 2.2 times more likely to be charged with a crime as a juvenile, controlling for other observable factors. That estimate is very close to the Rasanen et al. [1999] nding for Finnish males that we use in our calculations. 390
QUARTERLY JOURNAL OF ECONOMICS have access to legalized abortion. As of 1997, roughly 60 percent of crimes were committed by individuals born after legalized abortion, implying that (thus far) the hypothetical impact of abortion on crime is only 60 percent of the impact on affected cohorts, or about an 11 percent reduction. To the extent that other factors are correlated with both criminal propensities and abor- tion likelihoods (e.g., poverty, maternal education, religiosity), this rough estimate is likely to understate the true impact. 17 Given that the observed declines in crime in the 1990s are 30 – 40 percent, abortion may be an important factor in explaining the crime drop. In the next section we present empirical estimates of the impact of abortion on crime that are roughly consistent with these hypothetical calculations. IV. E MPIRICAL
E VIDENCE OF L EGALIZED
A BORTION
A FFECTING
C RIME
R ATES
We begin our empirical analysis by establishing a relation- ship between crime changes in the 1990s and legalized abortion in the early 1970s. We consider three different sources of varia- tion: the national time series of crime and abortion, differential crime patterns across early legalizers and other states, and the impact of state abortion rates (properly lagged) on state crime rates. In Section V we focus on arrest rates, which allows us to decompose the effect of abortion by the age of offenders. A. National Time Series Figure II presents per capita crime rates for the United States for violent crime, property crime, and murder for the period 1973–1999, as measured in the Uniform Crime Reports compiled by the Federal Bureau of Investigation. 18 Between 1973 17. These estimates will understate the true impact of abortion on crime if there are other factors beyond the four we explicitly considered that positively covary with abortion and crime, such as religiosity, poverty, or low maternal education. Indeed, this last factor was found by Rasanen et al. [1999] to be the single most powerful factor leading to criminality by the children. Moreover, to the extent that abortion reduces crime committed by other family members as a result of the bene cial effects of a reduction in family size (since larger family size increases the likelihood of criminality), this effect would also be missed. On the other hand, a countervailing force is that a reduction in the supply of criminals will induce higher returns to entry into the criminal occupations thereby offset- ting through recruitment the initial dampening effect on crime. One would sus- pect this effect to be limited to crimes involving active markets for illegal sub- stances (drugs) or services (prostitution). 18. Uniform Crime Reports compile the number of crimes reported to the 391
and 1991, violent crime nearly doubled, property crime increased almost 40 percent, and murder was roughly unchanged (despite substantial uctuations in the intervening years). The year 1991 represents a local maximum for all three of the crime measures. Since that time, each of these crime categories has steadily fallen. Murder has fallen by 40 percent and the other two categories are down more than 30 percent. The National Crime Victimization Survey (NCVS), which gathers information on self-reported crime victimizations, offers another perspective on national crime patterns in Figure III. According to victimization surveys, violent crime fell through the early 1980s, increased from that point until 1993, and fell sharply thereafter. Property crime fell throughout the period 1973 to 1991, and began to fall even more quickly thereafter. The crime declines in the 1990s are even greater using victimization data than the reported crime statistics. It is notable that the longer time-series patterns of UCR and victimization data do not match police in various crime categories each year. While the potential shortcomings of these data are well recognized (e.g., O’Brien [1985]), they remain the only source of geographically disaggregated crime data available in the United States. F IGURE
II Crime Rates from the Uniform Crime Reports, 1973–1999 Data are national aggregate per capita reported violent crime, property crime, and murder, indexed to equal 100 in the year 1973. All data are from the FBI’s Uniform Crime Reports, published annually. 392
QUARTERLY JOURNAL OF ECONOMICS closely, yet both demonstrate a distinct break from trend in the 1990s.
The timing of the break in the national crime rate is consis- tent with a legalized abortion story. In 1991 the rst cohort affected by Roe v. Wade would have been roughly seventeen years old, just beginning to enter the highest crime adolescent years. 19 In the early-legalizing states (in which slightly more than 20 percent of all Americans reside), the rst cohort affected by le- galized abortion would have been twenty years of age, roughly the 19. The Supreme Court handed down the decision in Roe v. Wade on January 22, 1973. Typically, there is a six-to-seven-month lag between the time that an abortion would be performed and the time that the birth would have occurred. Thus, the rst births affected would be those born in late 1973. If women who already had children in 1973 used abortion to prevent increases in family size, then abortion may indirectly lower criminality for the remaining children who will receive greater per child contributions of parental resources [Becker 1981; Barber, Axinn, and Thornton 1999]. Sampson and Laub [1993, p. 81] and Rasanen et al. [1999] nd that family size signi cantly increases delin- quency. Note that this family size effect suggests that criminality could be reduced for children who were born a number of years in advance of any abortion that prevents further increases in family size, and thus would allow the effect of abortion on crime to be observed prior to the time that the direct effect of abortion would be observed. F IGURE
III National Crime Victimization Survey, 1973–1998 Data are national aggregate per capita violent crime and property crime vic- timizations, indexed to equal 100 in the year 1973. All data are based on the National Crime Survey, conducted annually. Data have been adjusted to correct for a one-time shift associated with the redesign of the survey in the early 1990s. 393
peak of the age-crime pro le [Blumstein et al. 1986; Cook and Laub 1998]. The continual decrease in crime between 1991 and 1999 is also consistent with the hypothesized effects of abortion. With each passing year, the fraction of the criminal population that was born postlegalization increases. Thus, the impact of abortion will be felt only gradually. To formalize this idea, we de ne an index that is designed to re ect the effect of all previous abortions on crime in a particular year t. Obviously, recent abortions will not have any direct impact on crime today since infants commit little crime. As the postlegalization cohorts age, however, we can estimate the effect of abortion by seeing how much crime (proxied by the percentage of arrests committed by those of that age) is committed by the particular cohort. Thus, we de ne the “effective legalized abortion rate” relevant to crime in year t as the weighted average legalized abortion rate across all cohorts of arrestees, i.e., (1) Effective_Abortion t 5 O a Abortion* t2 a ( Arrests a /Arrests total ), where t indexes years and a indexes the age of a cohort. Abortion is the number of abortions per live birth, and the ratio of arrests inside the parentheses is the fraction of arrests for a given crime involving members of cohort a. In a steady state with all cohorts subjected to the same abortion rate, the effective abortion rate is equal to the actual abortion rate. For many years following the introduction of legalized abortion, the effective abortion rate will be below the actual abortion rate since many active criminal cohorts are too old to have been affected by legalized abortion. For instance, following Roe v. Wade, the actual abortion rate (per 1000 live births) rose to a steady state of about 400. Yet we estimate that the effective abortion rate in 1991 was only about 33 for homicide, 63 for violent crime, and 126 for property crime. Because property crime is disproportionately done by the young, the effect of abortion legalization is felt earlier. 20 The effective rates grew steadily, rising to 142, 180, and 252, respectively, by 1997. If legalized abortion reduces crime, then crime should con- tinue to fall (all else equal) as long as the effective abortion rate 20. Details of this calculation are available from the authors. This effective abortion rate includes legal abortion exposure prior to 1973 in the ve states that legalized in 1970. 394
is rising, precisely the pattern observed in actual crime data in Figures II and III. 21
As noted earlier in the paper, ve states (Alaska, California, Hawaii, New York, and Washington) legalized or quasi-legalized abortion around 1970; in the remaining states, abortion did not become legal until 1973. The staggered timing of the introduction of legalized abortion provides a potential avenue for assessing its impact. 22
quences of abortion legalization, Levine et al. [1996] analyze the fertility effects; Angrist and Evans [1996] study the impact on female labor supply; and Gruber, Levine, and Staiger [1999] examine the effect on a variety of measures of child welfare. For the purposes of analyzing crime, the comparison of early legalizers to all other states is less than ideal. First, criminal involvement does not jump or fall abruptly with age, but rather steadily increases through the teenage years before eventually declining. Early-legalizing states only have a three-year head start. Thus, it may be dif cult to identify an impact on overall crime rates since even in the peak crime ages three cohorts Yüklə 337,5 Kb. Dostları ilə paylaş:
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