That would be Cafehayek, run by economists Russ Roberts and Don Boudreaux. (I’ve asked Don if he’d post the wonderful letters-to-the-editors that he sends off to papers around the country and the world every day. They’re perfect examples of what a letter-to-the-editor should be: short, limited to one point, reasonable, and convincing.)
I am fortunate enough to attend the same university as the Cafe Hayek team. I read that blog daily. One time, I even saw both of them in real life! It was great.