1990s saw both the election and re-election of a "pro-choice"
the "pro-life" movement made considerable gains at the state and
local levels. Survey data indicate that by the end of the decade,
more people supported restrictions on abortion and fewer supported
Meanwhile, the actual number of abortions
declined during the decade. For the 46 states reporting data to the
Centers for Disease Control and Prevention in both 1990 and 1999, the number of
abortions fell from 1,035,573 to 854,416, a decline of 17.4 percent. This decline
translates into a reduction in the abortion rate from 20.61 to
16.62 abortions per 1,000 women between the ages of 15 and 44.
is the reason for this decline in the number of abortions? The
economy, which grew at a brisk rate during the mid- to late 1990s,
might be partly responsible. Studies indicate that abortion rates
decline during periods of strong economic growth. However, an even more
directly related factor might be the impact of legislation intended
to reduce the number of abortions.
study used data from the Centers for Disease Control and Prevention
(CDC) and the Alan Guttmacher Institute (AGI) to estimate how
state-level "pro-life" legislation affected abortion rates and
ratios. This paper
reports a number of findings based on these data. Among them:
- Those states that adopted pro-life
legislation during the 1990s experienced larger reductions in
abortion rates and ratios than those states that did not adopt such
- State laws restricting the use of Medicaid
funds in paying for abortions reduced the abortion rate by 29.66
and the abortion ratio by 2.08.
- The CDC data indicate that states that
adopted informed consent laws saw the abortion ratio drop by 11.69
and the abortion rate by 0.92. When AGI data are used, statistical
analysis indicates that informed consent laws have an even greater
effect, reducing the abortion ratio by 22.46 and the abortion rate
During the 1990s, there was a substantial
amount of pro-life legislative activity at the state level. For
- In 1992, virtually no states were enforcing
informed consent laws. By 2000, 27 states had informed
consent laws in effect.
- In 1992, no states had banned or
restricted the procedure widely known as "partial-birth abortion."
By 2000, 12 states had bans or restrictions in effect.
- In 1992, only 20 states were enforcing
parental involvement statutes. By 2000, 32 states were enforcing
major factors led to this increase in pro-life legislation.
First, in 1992, the U.S. Supreme Court in
Casey v. Planned Parenthood of Southeastern Pennsylvania abandoned
its trimester framework in favor of a doctrine of "undue burden."
In so doing, the Court found constitutional some of the policies
contained in Pennsylvania's Abortion Control Act. While the Supreme
Court did not overturn Roe v. Wade, the decision did give pro-life
legislators at the state level more freedom to enact laws designed
to protect the unborn.
instance, the only common forms of state-level legislation before
the Casey decision that consistently withstood constitutional
scrutiny were parental involvement requirements and restrictions on
Medicaid funding of abortions. However, Casey gave constitutional
protection to informed consent laws. These laws require abortion
providers to inform pregnant women about the health risks
associated with abortion, the development of their unborn children,
and resources for pregnant women and young mothers. Additionally, a
number of states passed "partial-birth abortion" bans before the
Supreme Court struck down Nebraska's ban in Stenberg v. Carhart in
Second, pro-life candidates made
considerable and lasting gains in state legislatures during the
1990s. While it is well-known that Republicans obtained control of
both the U.S. House of Representatives and the U.S. Senate in 1994,
the gains they made in the states have received considerably less
attention. Republicans obtained majority control in both chambers
of 11 additional state legislatures in 1994. Overall, the number of states where
Republicans controlled both chambers of the state legislature
increased from six in 1990 to 18 in 2000. In 2001, Republican state party
platforms for 48 of 50 states contained planks that supported
restrictions on abortion.
impact has all of this legislation had? Some academic studies
provide insights. Much of the academic literature that examines the
impact of state abortion policy focuses on parental consent
legislation and the extent to which states fund abortion through
Medicaid. Most of these studies argue that parental consent
statutes and restrictions on Medicaid funding reduce the number of
abortions that take place within the boundaries of a given state. However, researchers
are considerably more divided over whether or not these laws create
overall reductions in the number of abortions. This is because it
is possible for some people to circumvent these laws by obtaining
abortions in other states where the laws are more permissive.
"Mandatory Parental Involvement in Minors' Abortions: Effects of
the Law in Minnesota, Missouri, and Indiana," Charlotte Ellertson,
President and Chief Executive Officer of Ibis Reproductive Health,
pays special attention to the impact of Missouri's parental consent
law. She finds that
the number of abortions performed on minors decreased in Missouri
after the passage of the parental consent law. However, she also found that minors
were more likely to travel to other states to obtain abortions. In the article,
Ellertson argues that this increase in travel could be large enough
to offset the reduction in the number of abortions in Missouri.
Conversely, other studies arrive at
different conclusions. One study indicates that the number of
abortions performed on Mississippi residents, both in state and out
of state, declined after the state's parental consent statute was
other studies that have examined Minnesota's parental notification
law have found little evidence that minors are leaving the state in
great numbers to obtain abortions.
While these studies shed light on the
abortion patterns of the 1990s, many shortcomings exist.
First and foremost, none of the studies
examines the impact of "partial-birth abortion" bans or informed
consent statutes. Of course, some of the earlier studies examine a
time frame where few, if any, states had such laws. However, even
some of the later studies neglect to analyze their impact.
Second, state abortion data come from two
sources, the Centers for Disease Control and Prevention and the
Alan Guttmacher Institute. Most studies are limited because they
use only one of these data sources, each of which has shortcomings.
The Guttmacher Institute receives its data from surveys of abortion
clinics. While its method of data collection is more consistent
than the CDC's, the AGI does not collect data every year.
Conversely, the CDC does provide annual data, but its data
typically come from state health agencies. Since state health
agencies often change their methods for collecting and
disseminating data, their data may be somewhat less reliable.
Finally, many of these studies have a very limited scope, examining
only a small number of states that have enacted these policies. This can lead to
problems of selection bias. Still others consider only data from
relatively few years. As a result, these studies may not
have sufficient data to draw statistically meaningful
analysis attempts to overcome these limitations. It presents data
on abortion rates and ratios in every state from 1985 to 1999,
using data from both the CDC and the AGI. Furthermore, it takes
into account the impact of informed consent laws and "partial-birth
abortion" bans. Finally, it holds constant economic and demographic
factors that might cause fluctuations in the number of
empirical test of the effectiveness of pro-life legislation
involves a series of regressions on a dataset that includes
statistics on abortions for the years 1985 through 2000. Regression
analysis is well-suited to this type of research because it
simultaneously examines the effects of various factors on the
number of abortions in each state.
Separate regressions were run on four
dependent variables measuring the number of abortions within a
given state. The first set of dependent variables measure the state
abortion ratio as indicated by the CDC and Alan Guttmacher
Institute, respectively. The abortion ratio measures the number of
abortions for every 1,000 births. The second set of dependent
variables measure the state abortion rate as indicated by the CDC
and AGI. These variables measure the number of abortions per 1,000
women between the ages of 15 and 44. Combined, these four dependent
variables should help determine the impact of various forms of
variety of economic and demographic factors are held constant. To
capture the impact of the economy, this study includes each state's
per capita personal income growth in the regression model.
Additionally, a series of state-level variables measuring the
racial composition of women between the ages of 15 and 44 are
included in the model as well.
Three separate variables measure the
percentage of women of childbearing age who are between the ages of 15 to 19,
20 to 25, and 25 to 29, respectively. The hypothesis is that
younger women facing unexpected pregnancies would be more likely to
seek abortions than their older counterparts. As a result, holding
other factors constant, relatively higher percentages of younger
women would lead to increases in both abortion rates and abortion
Finally, a fertility variable, measuring
the number of births per 1,000 women between the ages of 15 and 44,
is included in the model. This variable serves as a proxy for the
number of pregnancies that are occurring. Fewer pregnancies would
result in fewer abortions. Similarly, if the fertility variable is
low, it might indicate that a higher proportion of pregnancies are
planned, which would also result in fewer abor-tions.
more interest in this study is the effect of different types of
state policies that deal di-rectly with access to abortion. The
re-gression analysis in-cludes four separate variables indicating
the presence or ab-sence of a particular type of policy.
first of these variables is the presence of a parental involvement
Parental notification requirements require minors either to notify
or to receive consent from one or both parents before receiving an
second policy variable is whether or not a state restricts funding
of therapeutic abortions through Medicaid. Most states will fund
abortions through Medicaid when the pregnancy is the result of
rape. Similarly, most states fund abortions that are necessary to
preserve the life of the mother. However, states differ as to
whether they fund therapeutic abortions.
Third is whether or not a state has an
informed consent statute. In Casey v. Planned Parenthood (1992),
the Supreme Court found that informed consent statutes were
constitutional. Informed consent statutes differ from state to
state. However, they all require women seeking abortions to receive
information about the abortion procedure. This can include
information about fetal development, the health risks involved with
obtaining an abortion, and the public and private sources of
support for single mothers.
fourth and final policy variable is whether a state has a ban on
"partial-birth abortions." About 12 states had "partial-birth
abortion" bans in effect between 1996 and 2000 before the Supreme
Court struck down Nebraska's "partial-birth abortion" ban in
Stenberg v. Carhart in 2000.
regression model used is a fixed effects model, in which separate indicator variables
are included for every state and year. Table 1 shows the estimated
effects of each of the four policies. The complete regression
results are in Table 2 in Appendix A.
figures in Table 1 measure the predicted change in a state's
abortion rate or abortion ratio after a particular piece of
legislation is passed. For instance, when data from the Centers for
Disease Control are used, the regression model predicts that the
passage of an informed consent law will lower the state abortion
ratio by 11.69 abortions for every 1,000 births and will lower the
state abortion rate by 0.92 abortions per 1,000 women between the
ages of 15 and 44. When data from the Alan Guttmacher Institute are
used, the regression model predicts that the passage of an informed
consent law will lower the state abortion ratio by 22.46 abortions
for every 1,000 births and will lower the state abortion rate by
1.57 abortions per 1,000 women between the ages of 15 and 44.
Overall, the results from the regression
analysis indicate that pro-life legislation has been effective at
reducing the incidence of abortion at the state level. In
particular, Medicaid funding restrictions appear to be especially
effective at reducing the number of abortions. When data from the
CDC are used, the model predicts that Medicaid funding restrictions
reduce the abortion rate by 29.67 and the abortion ratio by 2.08.
Moreover, these results are statistically significant. Furthermore, when AGI
data are used, the magnitude and significance of these coefficients
are similar. Overall, these findings are consistent with much of
the academic literature that examines the impact of Medicaid
particular interest is the impact of informed consent laws. These
laws are a recent policy innovation, and none of the other academic
studies examines their impact. When the CDC data are used, the
regression indicates that the passage of an informed consent law
reduces the abortion ratio by 11.69 and the abortion rate by 0.92.
When AGI data are used, the results indicate that informed consent
laws have an even greater effect, reducing the abortion ratio by
22.46 and the abortion rate by 1.57. All of these results are
statistically significant. These findings are particularly
interesting because over 20 states adopted informed consent laws
between 1992 and 1999. It seems likely that these laws played
an especially large role in the decline in abortions during the
Parental involvement laws appear somewhat
less effective than the other types of public policies. In all four
of the models, the coefficient for the parental involvement laws is
negative, which is consistent with expectations. However, while
some of the coefficients approach statistical significance, none
actually reaches it. It should also be noted that parental
involvement laws limit only the ability of minors to have
abortions. Examining their impact on minors who undergo abortions,
instead of all women who undergo abortions, would be a better test
of the effectiveness of such laws. Even so, parental involvement
laws do appear to reduce overall abortion rates and ratios, but
their impact is less statistically certain than the impact of
Medicaid funding restrictions and informed consent laws.
Finally, all the models predict that
"partial-birth abortion" bans reduce abortion rates and ratios. In
two of the four models, the coefficients do not achieve statistical
significance. However, it should be noted that the first
"partial-birth abortion" law was not enacted until 1996, and most
"partial-birth abortion" bans went into effect in 1997 and 1998. As a result, there
are relatively few data with which to evaluate their
number of abortions rose consistently throughout the 1970s and the
that trend reversed during the 1990s as the number of legal
abortions declined by 17.4 percent between 1990 and 1999.
There are a number of different reasons
for this decline. However, one factor that cannot be overlooked is
the impact of pro-life legislation in the states. By the end of the
decade, more states had adopted parental involvement requirements,
informed consent requirements, and "partial-birth abortion" bans. More important,
regression results provide evidence that each of these laws was
effective at reducing the number of abortions that took place.
Michael J. New, Ph.D., is a post-doctoral
fellow at the Harvard-MIT Data Center.
Appendix A: Regression Results
Regression analysis allows examination of
the effects of various factors on the central concern of this
paper: state-level abortion rates and ratios. Regression analysis
sorts out the effects of a single variable by holding constant the
effects of all other variables. Appendix A provides the
coefficients and standard errors for the various regression
coefficient of the independent variables provides an estimate of
how much a one-unit change of the independent variables changes the
instance, when data from the Centers for Disease Control are used,
the regression model predicts that a 1 percentage point increase in
state personal income growth will reduce the state abortion ratio
by 0.94 abortions per 1,000 live births and will reduce the state's
abortion ratio by 0.10 abortions per 1,000 women between the ages
of 15 and 44.
Similarly, when CDC data are used, the
regression model predicts that the passage of a parental
involvement law will lower the state abortion ratio by 7.22
abortions for every 1,000 births and lower the state abortion rate
by 0.54 abortions per 1,000 women between the ages of 15 and
fixed-effects GLS model with state and year indicator variables was
used, corrected for autocorrelation. The data were weighted by
following states did not report data to the Centers for Disease
Control and Prevention in 1998 and 1999: Alaska, California, New
Hampshire, and Oregon.
from Alaska are omitted because of data collection problems. Data
from Kansas are omitted as well. According to the CDC data, the
abortion rate jumped an astounding 69 percent between 1991 and
1999, and this cannot be traced to any shifts in economics, policy,
or demographics in Kansas or in neighboring states. Instead, it
appears that a large number of women seeking abortions choose to
travel to Kansas. Indeed, for every year between 1992 and 1999, the
CDC reports that over 40 percent of the abortions in Kansas are
performed on out-of-state residents. This is by far the highest
figure for any state.
Nearly all states reported abortion data
to the CDC through their central health agency. However some state
data were obtained from hospitals and other medical facilities.
Since these differences in reporting may bias the results, data
from the following states and years are omitted from CDC
New Hampshire 1981-1997
West Virginia 1981-1998
Alan Guttmacher Institute released state abortion data in the
following eight years: 1985, 1987, 1988, 1991, 1992, 1995, 1996,
and 2000. Data from Alaska are omitted because of data collection
problems. Data from Kansas are omitted because of the same outlier
problems described above.