The study examines the electoral success of major-party candidates in general elections for state legislative seats from 2003 to 2010. It found that candidates with names usually given to girls capture a smaller share of the vote than otherwise similar candidates with ambiguous or masculine names. "This result holds for both men and women, suggesting that voters, in this context, tend to discriminate against those sending relatively female-seeming signals: it is not failure to conform to stereotypes so much as sounding like one is female that reduces vote share," writes the study's author, Iowa State University political scientist Robert Urbatsch.
Urbatsch used Social Security Administration data, which records all given names of newborn children as well as their sex to determine the likelihood of a person's gender based on their name. Read more here. The overall estimated difference in vote share between a candidate with a feminine name and one with a masculine name is about 1.5 percentage points, enough to make a difference in many close elections. In rural areas, it's 2.5 percentage points.