Academic journal article Issues in Law & Medicine

Report of Peter R. Uhlenberg, Ph.D

Academic journal article Issues in Law & Medicine

Report of Peter R. Uhlenberg, Ph.D

Article excerpt

Fellow The Carolina Population Center University of North Carolina Chapel Hill, NC

Regarding Karlin et al. v. Foust et al. August 9, 1995

I. Change in the Number of Abortions Related to the Mississippi 24-Hour Delay Law

In Exhibits B and C of the Declaration of Stanley K. Henshaw, Dr. Henshaw presented the analyses that led him to conclude that the 24-hour delay law caused a decrease in the number of abortions obtained by women in Mississippi and that this decrease occurred because the law placed an increased burden on women seeking an abortion. The procedure he used to detect a change in abortion levels during 1992 was simple. The number of abortions performed in the first 7 months of the year (before the law changed) is used to obtain an "expected" number of abortions for the last 5 months of 1992 (after the law had changed). A ratio of expected abortions in the last 5 months to the number in the first 7 months is calculated by comparing abortions in the last 5 months to the number in the first 7 months of 1990, 1991 and 1993. Multiplying the ratio by the number observed in the first 7 months of 1992 gives the "expected" number in the last 5 months of 1992. The number of observed abortions in the last 5 months of 1992 is then compared to the "expected" number.

I have replicated the analysis reported in the first 4 rows of Table 1 in the Exhibit B article and obtained essentially the same results. There are, however, three basic problems with the procedure used to determine the expected number in this analysis:

First, it is not appropriate to use data from 1993 (after the law was in effect) to derive a base line seasonal adjustment ratio that is then applied to data obtained in 1992 before the law changed. This is simply not an acceptable practice. In the alternative procedure that I describe below, I use data from 1988 through 1991 to obtain a seasonal adjustment ratio that provides a more reliable estimate.

Second, a significant error is made by including data from the months of July and August in the analysis. The new law went into effect on August 8, 1992. It is inexplicable why August would be included in the analysis because part of the month preceded the change in law and part of it followed the change. In anticipation of the law, it is very possible that a significant number of women desiring an abortion around this time period advanced the timing of their abortions thereby increasing the number in late July. Therefore a reasonable test of change associated with the law would exclude data from July. In the alternative analysis shown below, I exclude the months of July and August for the reasons indicated above.

Third, and most important, by choosing to include data on abortions performed in the first quarter of 1992 (January-March) as part of the base for obtaining expected abortions later in the year, the authors greatly inflate the number of expected abortions.

Table 1
Replication of Regression Analysis Performed by Dr. Henshaw

Analysis of Variance
                      Sum of             Mean
Source      DF        Squares           Square   F Value   Prov>F

Model       13   185369.13889      14259.16453     4.259   0.0014
Error       22    73657.61111       3348.07323
C Total     35   259026.75000

      Root MSE    57.86254   R-square   0.7156
      Dep Mean   593.08333   Adj R-sq   0.5476
      C.V.         9.75622

Parameter Estimates

                 Parameter    Standard      T for HO:       Prob
Variable   DF    Estimate     Error         Parameter = 0   > |T|

INTERCEP   1     628.944444   43.12818898   14.583          0.0001
INTAUG92   1    -100.916667   40.91499256   -2.466          0.0219
JAN        1      75.736111   48.73835202    1.554          0.1345
FEB        1      97.611111   48.37924343    2.018          0.0560
MAR        1      29.819444   48.09808314    0.620          0.5416
APR        1      17. … 
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