Credits: Image: Christine Daniloff, MIT Previous image Next image Two of the studies described in this article have been published on a preprint server but have not yet been peer-reviewed by experts in the field. As the U.S. speeds up distribution of Covid-19 vaccines, the question of equity keeps surfacing. Who gets priority? If the pandemic is hitting certain communities harder, can they be adequately supplied with vaccine doses? What’s the best way to balance the needs of different groups within society? MIT economist Parag Pathak’s work emphasizes those questions — and helps tackle them. Over the last year, Pathak and a group of colleagues have developed an approach to the distribution of vaccines and other medical goods that is being used in Massachusetts, New Hampshire, and Tennessee.