MIT's Jonathan Gruber is among the leading health economists in the country. He's worked extensively with candidates of all stripes, was a prime architect of the Massachusetts plan, and has conducted an unsettling amount of the most used, most respected, current research in the field. He's asked me to post this response to Kit Seelye's atrocious article on the various Democratic health plans, in which he dives into the misuse of the research on auto insurance, explains what's actually going on in Massachusetts, and gives what is the consensus view on mandates and coverage. I'm happy to do so. His full letter is below the fold.