A while back, when I wrote about Denmark's ability to make a large welfare state co-exist with economic growth, my colleague Brad Plumer suggested I check out the work of Peter Lindert. Lindert, an economist at the University of California-Davis, wrote a highly acclaimed book called Growing Public: Social Spending and Economic Growth since the 18th Century. In it, Lindert demonstrated that a large social welfare state needn't sink national economies, as long as the government spends its money efficiently and structures the necessarily high taxes in a way that's favorable to growth. (This review of the book has an excellent summary of Lindert's arguments.) This, of course, is precisely what Denmark and the Nordic countries have been doing--which is why Lindert's work would have been so helpful to my argument. But, as often happens, I didn't actually have time to read the book before my deadline. So I am pleased to see Lindert's work appear prominently in today's Washington Post column by Sebastian Mallaby. And I am even more pleased to see Mallaby making the same argument that economists on the center-left (as well as yours truly) have been making for a while: That it's time to talk seriously about raising taxes to pay for infrastructure and programs like universal health insurance, which can ultimately make the economy more productive, particularly if policymakers want to avoid the kind of "pre-market" interventions (like restrictions on free trade) that most mainstream economists think really could stall economic growth. I don't agree with everything in Mallaby's column. Among other things, I think he and I disagree about how generous we can afford to be towards the elderly. But precisely because Mallaby holds more conservative views on these and other matters, I take this column as a sign--a most welcome sign--that the decades-old taboo on taxes, which has paralyzed the debate over public policy in this country, may finally be weakening. --Jonathan Cohn