In this episode of “The Opinions,” David Wallace-Wells, a writer for Times Opinion, talks with the economist Emily Oster about Robert F. Kennedy Jr.’s policy priorities as secretary of health and human services and what the changes he’s wrought — from canceling mRNA vaccine research to phasing out food dyes — mean for our health. Robert F. Kennedy Jr.’s Impact So Far: ‘The Worst Possible Case’ David Wallace-Wells and Emily Oster argue that the effects of MAHA will be long-lasting. Below is a