At the Republican debate Saturday night, Mitt Romney shared some of the advice his father, Gov. George Romney, shared with him about running for office. “Mitt,” he said, “never get involved in politics if you have to win an election to pay a mortgage.”

New research suggests there’s some truth to the elder Romney’s counsel: Higher pay for legislators correlates with politicians being worse at their jobs and an overall decrease in the quality of politicians elected to office.

The study, lead by Columbia University’s Richard Fishman, looks at salaries paid to members of the European Parliament, the legislative chamber of the European Union. It consists of 736 members elected from the European Union’s 27 member countries. After a few years of allowing member countries to set salaries, the European Parliament set a standard salary for its members. For some it was a pay raise; for some, a decrease. And that created a natural experiment to look at how a change in salary impacted competition for elected office.

There is, however, a downside to this increased competition: Fishman and his team find that higher paid legislators also tend to be of lower quality, as measured by the ranking of the university they attended. On some indicators, they’re no better at thier jobs, not showing up to vote anymore than they did at a lower pay grade. “Overall, our evidence suggests that higher salaries lower the quality of elected [legislators],” they write. A salary bump looks to be a bit a double-edged sword in this regard, increasing competition for office but decreasing the quality of those who ultimately serve.

CORRECTION: A previous version of this post inaccurately described this study’s findings on how salary impacts absenteeism and shirking of responsiblities among legislators. It does not impact such behaviors.