BESIDE the riotous, relentless battle over Obamacare, a more tempered debate over health has been underway. Since the recession, health spending has grown slowly. On January 6th the number crunchers at the Centres for Medicare and Medicaid Services (CMS) released their newest annual figures. In 2012 spending rose by just 3.7%, to $2.8 trillion. That compares with growth of 9.7% in 2002. Importantly, America’s health spending in 2012 grew more slowly than its economy. The debate is whether the slowdown is merely a cyclical blip. This seemingly dry question is hugely important. Health spending threatens America’s long-term economic health, according to the Congressional Budget Office. Trends in spending will also shape the fate of an industry that accounts for nearly one-fifth of the world’s biggest economy. If the sector has seen structural changes in how individuals buy care and how doctors and firms sell it, that would be a big deal.

Academics have written extensively on the subject. In May David Cutler and Nikhil Sahni of Harvard reported that the recession accounted for just 37% of the recent slowdown in health spending. They posited that more than half of the deceleration could be explained by more persistent changes, including skimpier insurance (which prompts individuals to buy less care), more efficient clinics and the slower development of pricey new technologies. If such trends continue, they suggested, the government’s spending on health from 2013 to 2022 could be $770 billion less than expected.

Michael Chernew, also of Harvard, has noted that from 2009 to 2011 health spending per person grew at about half the rate of the prior ten years. He reported that less generous insurance accounted for about one-fifth of the slowdown from 2007 to 2011. Other factors, such as contracts that reward doctors for providing better care rather than lots of it, could continue to dampen growth in future.

The new report from CMS provides more data for academics to munch on. Some trends seem to have staying power. CMS explained that high-deductible insurance plans—which make consumers pay for care with cash, up to a certain point, before insurance kicks in—helped slow the growth of insurance premiums. Other trends seem more transient. For example, spending on drugs has recently been anaemic. Many blockbuster medicines have lost their patents in recent years, so consumers have switched to cheaper generics. As pharmaceutical companies sell new, expensive specialty drugs, spending may pick up.

The big unknown is how Obamacare will affect this. Though the White House was quick to credit the law with helping to slow spending, CMS was more cautious. Furthermore, CMS’s new numbers are for 2012; Obamacare’s main provisions did not take effect until this month. The likely answer is that spending will jump this year, as Obamacare expands insurance coverage. But some changes, including more efficient clinics and penny-pinching consumers, will mean spending will rise more slowly than it might have otherwise.