Answer

IRV has not been shown to decrease turnout. However, the full extent of the impact of IRV on voter turnout is not known.

IRV can improve turnout by consolidating low-turnout primary and runoff elections into a single higher-turnout general election. Most places that adopt IRV make this switch.

Characteristics that are independent of the type of election (like competitive campaigns and media attention) are the strongest drivers of voter turnout in general elections. This can make it difficult to control for the impact of IRV.