You can probably count on one finger the times that Paul Krugman, the Times columnist and Nobel-prize winning economist, and David Stockman, Reagan’s budget director, have agreed on anything. But they are in violent agreement about the fiscal irresponsibility of the tax-cut deal. In urging Obama to reject the deal because of his concern the tax cuts will likely become permanent, Krugman wrote on Monday that “giving in to Republican demands would mean risking a major fiscal crisis — a crisis that could be resolved only by making savage cuts in federal spending.”