How to quantify gerrymandering? Reporters find a way

An Associated Press team of reporter David Lieb, data journalist Meghan Hoyer and interactives producer Maureen Linke, applying a new statistical method that calculates partisan advantage, analyzed U.S. House and state legislative races across the country last year and found that redistricting controlled by Republicans had given their party a distinct advantage and one that will be hard for Democrats to overcome in upcoming election cycles.Their multiformat report – including easy-to-grasp interactives and a trove of localized data – is the Beat of the Week.

Conceived by Lieb, a Missouri-based member of the State Government Team, the story did something no one else has attempted. The AP scrutinized the outcomes of all U.S. House and about 4,700 state House and Assembly seats up for election in 2016. The “efficiency gap” statistical method Lieb used is designed to detect cases in which one party may have won, widened or retained its grip on power through political gerrymandering. The analysis found four times as many states with Republican-skewed state House or Assembly districts as Democratic ones. Among the two dozen most populated states that determine the vast majority of Congress, there were nearly three times as many with Republican-tilted U.S. House districts. Traditional battlegrounds such as Michigan, North Carolina, Pennsylvania, Wisconsin, Florida and Virginia were among those with significant Republican advantages in their U.S. or state House races. All had districts drawn by Republicans after the last Census in 2010.

The constitutionality of partisan gerrymandering is at issue in a case before the U.S. Supreme Court this fall, with a decision due before the next round of redistricting following the 2020 Census. If partisan gerrymandering “goes unchecked, it’s going to be worse – no matter who’s in charge,” said one academic source quoted in AP's story. The reporting task was daunting. “Gathering and cleaning up the election data for thousands of state house races around the country was a big undertaking,” Lieb said. And that was just the start. Lieb worked with the researchers who developed the efficiency gap method and did the math and computations for the project. Hoyer, based in Washington, fact-checked and coordinated distribution to AP members.Hoyer also worked with Linke to determine the best way to visualize the complicated subject. Fine-tuning ideas discussed in their meetings, Linke created a chart with contextual elements and pop-up boxes that let readers easily make sense of how gerrymandering may have skewed representation in their state or congressional district.
Play was phenomenal. The story ranked No. 4 for the week on AP Mobile and appeared on 37 front pages on Sunday and 55 more on Monday. Several used it as a springboard for editorials, including one in the St. Louis Post-Dispatch headlined, “We all lose when gerrymandered districts lead to lopsided representation.”For applying cutting-edge data analysis and old-fashioned reportorial digging to produce a unique and accessible examination of gerrymandering’s impact, Lieb, Hoyer and Linke win this week’s prize.

Listen to Lieb present the findings of the AP analysis on Philadelphia public station WHYY’s “NewsworksTonight.”