When classes resume in January, colleges should start offering financial rewards to students to stay Covid-negative. My column in the NYT. https://www.nytimes.com/2020/12/29/business/rewards-college-students-coronavirus.html

Many colleges already require weekly testing of students on campus. They can add cash rewards for testing negative, maybe $50 a week. Makes sense even for narrow budget reasons: no big outbreak=no lost housing revenue. Plus reduces community spread.

They can even design the rewards in a way that works particularly well for people who like instant gratification — which is probably a good description of the people we're worried about, e.g., college students going to crowded parties.

The insight about incentive design is from a study by @shilpa_555, @RDizonRoss & @ariel_zucker that encouraged adults in India to walk >10,000 steps a day. Study: http://bit.ly/RDRincentives 
RDR's thread on it: https://twitter.com/RDizonRoss/status/1257341005126406147

The walking study compares "separable" contracts that pay you for each period of good behavior (day you walk) vs. "time-bundled" contracts that pay you for *repeated* good behavior, e.g., paid if you walk >=4 days in week.

"Time-bundled" contracts work well for impatient people, i.e., those who put a steep discount on the future. Key insight: For people who discount the future a lot, being diligent in the future doesn't seem so bad. The incentive designer can leverage that fact.

Impatient people highly value the option of getting paid for being diligent *in the future*, so they are willing to pay a high price for that option. In a time-bundled contract, the price you have to pay is to be diligent *now*, i.e., overcome your current procrastination.

This nice insight suggests you should offer college students a big lump sum if they stay Covid-negative all semester. But that goal is daunting, so some students might not even try. Happy medium: Offer $250 for testing Covid-neg for 5 weeks in a row; then keep repeating that.