Robert Moffitt noted that the magnitudes of these effects are still quite uncertain. Not only are there still quite a few studies showing no significant effect of the welfare system (see Table 2), but also many of these studies use stronger methodologies and are sounder than the others (as in the results for whites). In addition, of the studies that find significant effects, some find the size of the effect to be very modest in magnitude compared with other influences on fertility and marriage, although some find sizable effects as well.
The final point emphasized by Moffitt is that, even though there is a rough consensus that welfare has some effect on marriage and childbearing, the welfare system cannot explain the rise in nonmarital childbearing over the 1980s and 1990s because welfare benefits have been falling over that period (see the section above on trends in the welfare system). To explain that rise, some other factor must have been at work. Leading candidates are a rise in the earning power of women, even low-income women, leading them to be able to support themselves and their children without the earnings of a husband; a decline in the incomes of less educated men, which could have decreased their attractiveness as marital partners; and a decline in the numbers of men available, a hypothesis suggested for disadvantaged blacks (Wilson, 1987). There is considerable research on these other factors, but less research that compares welfare benefits to those facts and attempts to parcel out their relative influences (studies that have attempted to control for some of these other factors include Acs, 1995, 1996; Danziger et al., 1982; Darity and Myers, 1993, 1995; Duncan and Hoffman, 1990; Hoffman and Duncan, 1988, 1995; Lichter et al., 1996; Lundberg and Plotnick, 1990; Schultz, 1994). At the workshop, June O'Neill emphasized that the decline in male wages may have been so great than welfare benefits could have increased in relative attractiveness, whereas William Darity believed that it has been the decline in the pool of marriageable men that is the most important.