Among the many observers who pointed out flaws in Stassen's approach was the National Right to Life Committee. The Alan Guttmacher Institute released research in 2005 refuting Stassen's conclusions. Nonetheless, Stassen has issued several more statements affirming his original thesis and making additional claims.

Since Dr. Stassen cites my web site in his defense of his claimed abortion increase, I thought I'd weigh in. My training includes not just statistical analysis but also understanding the potential limits of such analysis. Stassen's analysis fails for two main reasons:

1. His data is limited, and he fails to recognize how the limitations of the data damage the validity of his quantitative conclusions.

2. He focuses on a handful of influences on abortion rates to the exclusion of others. He then erroneously claims a casual relation based on a correlation between his chosen influences and his fictitious abortion increase.

I have received questions relating to Stassen's articles and hope to soon complete an extended analysis. For now, I would point out the following:

• Stassen's original claim is based on 16 states and for these is a supposed net increase of 6,007 abortions from 2001 to 2002. (He gives an incorrect total of 6,207 in more than one place.) Most of Stassen's increase is due to Arizona and Colorado (5,465 net increase). For these two states, the 2001 total is 30% lower than 2002--and also 42% lower than 1998. An attentive user of this data should question this profound and temporary decrease, since it implies a problem with data collection. This problem is reportedly confirmed by both AGI and the respective state agencies. Thus, the data for Arizona and Colorado should have been rejected. This would change his total to an increase of 542. Stassen in his response justifies including these states so as not to introduce a "subjective bias", but by blindly including these states, he actually introduces a systematic bias in favor of an increase.

• Stassen does not use consistent data. Some states report all in-state abortions, some report only abortions by residents. For states where both types of data are reported, he is inconsistent in which set he picks. The result is to inflate his total. For the 16 states, the actual reported net change from 2001 to 2002 would be anywhere from a decrease of 1,970 to an increase of 5,782, depending on which data is preferred. Again, the result of his selective data use here is to introduce a bias towards increasing abortions.

• At the time of Stassen's original research (mid 2004), my web site included 2001 and 2002 data for ten additional states: Arkansas, Georgia, Iowa, Kansas, Montana, North Carolina, Oregon, Utah, Vermont, and Virginia. Of these states, 6 posted decreases and 4 posted increases from 2001 to 2002. For all 24 states (these 10 and Stassen's 16 less Arizona and Colorado), we get a net decrease of at least 2,845 from 2001 to 2002. This projects to a nationwide decrease of 8,000, comparing well to the AGI estimated decrease of 10,000 from 2001 to 2002. Regardless of why Stassen did not include these 10 states, the result was to introduce a systematic bias towards increasing abortions.

• Stassen cites a 1% margin of error in their recent estimates for 2001 and 2002 and says "So the decline of 0.9% [from 2001 to 2002] is within the margin of error." He does not acknowledge that his claimed 1.5% increase is well outside this margin of error.

• Stassen significantly misapplies statistical tests when he claims "greater than 99.9999% confidence that [the 16 states] represent the fifty states." The worst error is in treating the reported state figures as actual results, rather than the limited sampling of the actual results they are. In this sense, the figures are a known-to-be flawed sample of 400,000 women, not a representation of 30,000,000 women as he claims. Applying a different treatment to the data from the 16 states, I obtain a 42% probability of a decrease instead of an increase, and a 53% probability that Stassen's nationwide estimate is an overestimate. (Note that I do not claim my treatment is statistically valid, just that Stassen's is invalidated by poor treatment of the deficiencies of the reported figures as well as misapplication of statistics.)

• Stassen claims that of women obtaining abortions, "two-thirds...do not see how they could afford to raise the child" and "half..say they do not have a reliable mate", citing Minnesota Citizens Concerned for Life. This same site, citing AGI, says that 75% of women "say having a baby would interfere with work, school, or other responsibilities." Because these percentages include women each giving multiple reasons, it would be erroneous to select a single reason as decisive in these decisions to obtain abortions. In a 1988 AGI survey, only 21% cited economics as the most important reason, and only 13% cited issues with the mate as the most important reason. In data reported by the state of Minnesota, from 1998 to 2003 only 25.8% of women reported economic reasons and only 18.9% reported relationship issues or single status as a reason. In data reported by the state of South Dakota, from 1999 to 2003 only 28% of women cited economic reasons for their abortions.

• Stassen's claims regarding economics are not accurate; they repeatedly correspond more to false claims by the Democratic party than to actual data. For example, real income for the lowest quintile of U.S. households has been declining from a peak in 1999, before Bush came into office. Further, from 2001 to 2003 the decline in real household income has been higher for the wealthiest quintile than for the other four quintiles. This point contradicts claims involved in his farfetched linkage between CHIP budgets and tax policies.

• Stassen claims more abortions result from lack of a "reliable husband or mate", which in turn he claims results from high unemployment. He specifically cites reduced marriages in his 16 chosen states. However, the decline in marriages and marriage rates has been mostly ongoing since the early 1980s. Marriage indicators do not correlate with either abortion numbers, abortion ratios, or economic conditions. Abortions fell during the largest rise in unemployment since Roe v. Wade--which occurred in the early 1980s. There are other social factors at work here, which Stassen ignores.

• Stassen errs in citing abortion rates and social policies in other countries in support of his thesis. He cites Belgium and the Netherlands, claiming their abortion ratios are lower because of "strong economic support as well as health insurance" for mothers. However, many other countries have similar social policies and nonetheless have abortion ratios comparable to the U.S. Belgium and the Netherlands are distinguished by having a mandatory waiting period for abortions. In other words, legislative restrictions on abortion rather than socialist economic practices are best correlated with lower abortion rates.

• Stassen repeatedly ignores an important dictum in science: correlation does not prove casuality. For example, he claims an infant mortality increase in 2002 "supports [his] contention that mothers and babies have been undermined economically." He has offered no evidence for a casual connection here.

Stassen accuses his critics of placing partisan politics before pro-life policies. The data suggests that this criticism would better fit Stassen himself. His data analysis was poorly carried out, and even worse Stassen ignored the deficiencies in his approach in his zeal to support his thesis of federal social policy being the greatest factor in abortion rates. His selective use of evidence indicates no acknowledgement of factors which are better correlated with lower abortion rates--mandatory waiting periods, for one. He offers no support to such policies that offer greater promise for reducing abortions.

In fact, it seems clear that Stassen's analysis was colored by his desire to influence policy: "Had my esimate that abortions...probably increased...turned out to be right, it would have put significant pressure on the Bush administration to give more support to mothers and babies... You would expect consistently pro-life advocates like me to hope I was right." Unfortunately, the facts got in the way, it seems. This is a particularly disturbing aspect of this episode. That Stassen, a Christian ethicist, should insist on faithfulness to false data to further a particular agenda, is a denial of ethics and of the Christian goal of truth.

© 2005 by Wm. Robert Johnston.
Last modified 13 July 2005.
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