A study released Monday suggests that being honored with a major scholarly prize may not improve the winner's productivity. George J. Borjas of Harvard University and Kirk B. Doran of the University of Notre Dame analyzed the impact of winning the Fields Medal, which is awarded every four years to the most talented mathematician under 40. Borjas and Doran compared the productivity (in research output) of mathematicians who won the medal and contenders who did not. (They found other prizes that are good predictors of winning a Fields, and so identified likely winners.) The research found that the winners and the contenders had nearly identical productivity before the winners won the Fields. But after winning the Fields, mathematicians see a decline in productivity. They also show more "cognitive mobility," working in new areas, which the authors note likely forces them to take longer to make findings and write papers. The paper was published by the National Bureau of Economic Research (abstract available here).