Research investigating whether female legislators provide more effective substantive representation on women's issues than their male colleagues faces a significant methodological hurdle. Models used to estimate the effect of gender on representation inevitably omit constituency variables that affect the character of legislators' decisions and are also correlated with gender, potentially biasing the estimates of the effect of gender. Employing a quasi-experimental research design as an alternative strategy, the authors remove this hurdle and estimate the influence of gender on representation free from this potential bias. The authors find that gender does affect representation and observe critical mass effects.
Congress, descriptive representation, substantive representation, women and politics, agenda setting
Do female members of Congress provide more effective representation of women's interests than their male colleagues? Prior research generally indicates "yes" with debate as to whether having a substantial number of women in the legislative body, or a "critical mass," encourages congresswomen to devote their scarce time and legislative resources to enhancing the quality of representation that they provide women (e.g., Bratton 2005; Grey 2006; Reingold 1992, 2000; Saint-Germain 1989; Thomas 1994). Scholars observe this benefit of descriptive female representation across a host of issues (Barrett 1995; Carey, Niemi, and Powell 1998) but especially with respect to women's and feminist issues (e.g., Burrell 1994; Carroll 2001; Dolan 1997; Swers 1998, 2002). Female legislators also voice distinct policy priorities from men (e.g., Thomas 1994; Thomas and Welch 2001), view women outside their district as constituents (Carroll 2002), and expand the agenda to include women's perspectives (e.g., Dodson 2005, 2006; Kathlene 1994; Reingold 1996; Rosenthal 2000; Wolbrecht 2002, 193). In summary, "women legislators tend, more often than men, to make priorities of issues important to women and to introduce and successfully usher those priorities through the legislative process" (Dodson 2001, 226).
This conclusion comes from studies that employ an array of methodological strategies. Nonetheless, these strategies regularly fail to differentiate between the effect of a legislator's gender on her or his representational behavior and the demands of one's constituency. The inferential dilemma is profound: "The omission of constituency preferences from models of gender differences in legislators' policy attitudes" may produce premature conclusions where "the impact of gender may have been overestimated" (Poggione 2004, 306). The relatively few studies that work to account for constituency demands in assessing women's legislative behavior thus offer a substantial leap forward for understanding women's substantive representation (e.g., Bratton and Haynie 1999; Poggione 2004; Swers 1998, 2000; Thomas and Welch 1991; Tolleson-Rinehart 2001). Inferential dilemmas persist, though, as these inquiries rely almost solely on standard sampling techniques and multivariate models. Valid data that accurately capture the full political landscape and constituency characteristics for all 435 districts simply do not exist. This means inevitable problems of measurement error and an inability to determine how omitted variable bias is at play (Clarke 2005, 2009).
This article capitalizes on experimental logic to offer a different empirical solution to the problem of controlling for constituency. We utilize a quasi-experimental research design composed of longitudinal data. The sample includes all pairs of House members serving during the 1970s, 1980s, and 1990s during which a district transitioned from having a woman serve it immediately before and/or immediately after a man (omitting transitions in which districts are changed due to redistricting). After identifying these pairs, we recorded the number of bills sponsored by the members on "social welfare" and "feminist" issues during the relevant congressional sessions employing Swers's (2002) criteria for coding these issues. …