Al Roth (the George Gund Professor of Economics at Harvard) is extremely well known in the fields of game theory and market design. For just a few examples, he's published highly cited work on the market for donor organs, matching medical students with residencies, and matching public school children with schools. He also
Now he has a blog, titled (appropriately enough) Market Design. It's definitely worth a look-see.
HT: Marginal Revolution