Effects of price and availability on abortion demand.

I. INTRODUCTION

Following the Supreme Court's decision in Roe v. Wade in 1973, the rate of legal abortion in the United States increased from 16.3 abortions per 1,000 women aged 15-44 in 1973 to 29.3 in 1981, but then declined to 27.3 by 1988. (Data are from the U.S. Statistical Abstract, various issues.) Throughout this period, the abortion rate among whites consistently was less than half the rate among non-whites.

The national abortion rate has not changed dramatically since 1979, but considerable variation in abortion rates across states persists. In 1987, abortions per 1,000 resident women aged 15-44 ranged from 9.0 in South Dakota to 45.1 in California. However, in 1987 abortions per 1,000 women aged 15-44 by state of occurrence varied from 5.7 in Wyoming to 45.0 in California. Thus, for two states, Kentucky and Wyoming, over 30 percent of the resident women who had an abortion in 1985 obtained abortion services in another state. In 10 states, more than 20 percent of resident women who obtained abortions went out of state for abortion services (Henshaw and Van Vort, 1992).

This paper analyzes the demand for abortion services. Knowledge of the factors affecting the demand for legal abortion services is important for several reasons: (i) The use and availability of abortion services is a significant policy issue in and of itself (Deyak and Smith, 1976). (ii) The increasing availability of legal abortion services in the 1970s was associated with significant reductions in abortion-related mortality among pregnant women (Tyler, 1983; Parker, 1989) and, less obviously, with improvements in infant health (Corman et al., 1987; Grossman and Joyce, 1990; Ohsfeldt and Gohmann, 1992). (iii) Abortion availability also can affect fertility rates (Coelen and McIntyre, 1978; Frejka, 1983). As states are given more discretion to regulate abortion availability, the use of abortion services may change. Thus, abortion regulation may affect women's and infants' health as well as fertility rates. The magnitudes of these effects critically depend upon the nature of abortion demand.

The abortion demand model here uses state-level data pooled over time and examines abortion rate components--abortions per pregnancies and the pregnancy rate. A fixed-effects model design controls for unobservable variables affecting abortion attitudes and abortion use across states. The analysis compares results from a single cross-section of state-level data to the pooled model results. Findings indicate that the fixed effects model is more robust with respect to the specification of the independent variables in the abortion demand model.

II. BACKGROUND

One can analyze abortion demand by using economic models of fertility and fertility control (Becker, 1981; Bryant, 1990). Analysts often model fertility in a household production framework, where individuals determine the choice of a contraceptive method by considering its benefits and costs with respect to fertility control. One can think of abortion as a method of secondary contraception for fertility control. Once an unintended pregnancy has occurred, three options are apparent: (i) terminating the fetus, (ii) carrying to birth and keeping infant, or (iii) relinquishing the infant for adoption. Individuals--even adolescents with unintended pregnancies--so rarely select the adoption option that pregnancy resolution studies often ignore it (Leibowitz et al., 1986). Individuals may base the abortion decision on a comparison of the costs and benefits of terminating the pregnancy relative to carrying to birth.