In today's contentious political climate, when hardly anyone agrees on anything, here's a rare subject of consensus: Health spending is slowing, and almost everyone thinks that's a good thing. Aside from relieving pressures on federal and state budgets, it could help reverse stagnant wages by moderating the cost of employer-paid insurance. Compensation would shift from insurance to wages. What the experts don't agree on is who (or what) caused the slowdown and whether it will continue. First, the basic figures. In each of 2009, 2010 and 2011, U.S. health spending increased a modest 3.9?percent, virtually identical with the slow growth of the economy (gross domestic product, or GDP).