This is a guest post by Monica Prasad, who wrote an op-ed in Tuesday's New York Times called "On Carbon: Tax, Don't Spend." It elicited responses from David Roberts and Charles Komanoff. ----- Thanks to David and Charlie for picking up on and responding to my carbon tax op-ed. I've learned a lot from Grist, so I was happy to see this. Some responses to their criticisms. David's beef is with the word "spend" in the headline. I agree the headline is stupid, and it was not my idea. It implies that I'm advocating hoarding the revenue. Instead, I was …