…..[W]e decided to test the notion that third-party candidates increase turnout in presidential elections.
To start, we collected voter turnout data going back to the election of 1868. That election was the first after the Civil War and represents the earliest days of the modern two-party system.
We looked at how voter turnout interacted with the voting performance of third-party candidacies. We took into consideration the expansion of the voting franchise through the 15th Amendment, which granted universal male suffrage; the 19th Amendment, which extended the vote to women; the 26th Amendment, which lowered the voting age to 18; and the Voting Rights Act. We also compensated for historical and demographic trends.
We found that not only do third-party candidacies fail to increase turnout, they are actually associated with a statistically significant reduction in turnout. Put simply, fewer people vote in elections in which third-party candidates receive a substantial portion of the vote…..