Barbara Palmer, an associate professor of political science at Baldwin Wallace University in Berea, Ohio, and Dennis Simon of the Southern Methodist University, co-authored the book "In Women and Congressional Elections: A Century of Change." They analyzed data on nearly 40,000 candidates in the past 100 years.
"As it turns out, female incumbents have to work harder than male incumbents to hold onto their seats," Palmer said in a statement. A female incumbent is more likely to be challenged in her own primary, the research found.
The book also identifies "women friendly" congressional districts, districts where women are more likely to win.
"The districts where women successfully run for office are different from the districts where men successfully run," Palmer said. "Female candidates from both parties are more likely to win in districts that are more urban, more educated, wealthier and more racially and ethnically diverse."
Given this, redistricting can shape the success of female candidates; making it possible to "gendermander." For example, in Ohio preliminary analysis of the latest round of redistricting shows that female incumbents in the state House of Representatives were more likely to have their districts substantially redrawn than their male counterparts.