Public trust in democratic processes and institutions in the United States continues to decline. A major motivation for this erosion of trust is gerrymandering, a longstanding political strategy in which state legislatures manipulate district lines to gain a partisan advantage and reduce electoral competitiveness. In an effort to combat gerrymandering, lawmakers (and, in some cases, citizens via ballot measures) across the country are adopting independent redistricting commissions (IRCs), bodies separate from the legislature that are responsible for drawing new district lines for their state every ten years. Scholars who have studied IRCs have found varying degrees of success in the eight states that have used these commissions. While existing research on IRCs generally concludes that they can be effective in reducing partisan bias in electoral districts and increasing competition, we do not know which specific aspects of the IRC design are most responsible for this effectiveness. This paper addresses this gap in the literature by thoroughly examining the composition and design of each IRC, including the selection processes, standards for public engagement, rules for partisan makeup, independence, and voting processes. 

I argue that IRC composition matters greatly. Those IRCs that have an impartial member selection process, facilitate public engagement, have a balanced partisan makeup, and use consensus or supermajority based voting rules will be more effective at reducing the partisan bias of maps and increasing electoral competition. This research offers a more detailed understanding of what makes IRCs more or less effective in mitigating gerrymandering by identifying potential patterns.