There's nothing more selfish you can do than come towork sick. You may get a gold star for showing yoursniffling face at the office and soldiering through theworkday to prove your value—but everyone around you just gets sick.You're an inconsiderate work hazard.

When people bring their infectious illness to work, itspreads—and when sick people don't have a financial incentive toshow up to work, fewer people get sick, according to a newworking paper by the nonprofit National Bureau of EconomicResearch.

The researchers studied U.S. cities with paid sick-leavemandates and, using Google Flu Trends data at the cityand state level from 2003 to 2015, looked for changes in flurates after those mandates went into effect. The cities thatadopted paid sick-leave mandates in that timeframe saw flu cases drop by about 5 percentafter their laws took effect. For a city of 100,000people, that comes out to 100 fewer infections per week, theresearchers estimate.