I don’t know whether Emily Post has any tips for breaking the ice over lunch with your just-vanquished foe. But I have just the thing if President Barack Obama was serious about asking Mitt Romney to “work together to move this country forward.”

Romney was once a world-class management consultant with a legendary appetite for “the data.”

His private equity success was due partly to his knack for identifying and purging inefficiencies from bloated, underperforming enterprises.

It’s time, therefore, to set him loose (analytically speaking) on the mother of all domestic challenges: America’s radically inefficient health care system.

Outsize U.S. health costs have killed wage growth, wrecked public budgets and diverted trillions in resources from other purposes.

They also warp every aspect of public debate — for example, in today’s “fiscal cliff” standoff, the fact that both parties are scared to shave Medicare’s growth ignores the fact that, compared with every other rich country on Earth, we already spend vastly more on each senior than is needed for high-quality care.

As can never be said often enough, we spend 17 percent of our gross domestic product on health care while most nations in the Organization for Economic Cooperation and Development spend around 11 percent with similar outcomes (and mighty Singapore spends just 4 percent).

The political problem, of course, is that every dollar of health care “waste” is someone’s dollar of income. To reframe the debate, we need an authoritative analysis that identifies exactly what’s driving our costs so much higher than everyone else’s — as well as a set of lessons we can learn from the nations that do more (including insure everyone) with much less.

Hence Romney’s new mission, if he’ll accept it. Obama should convene a presidential commission on national health costs, to be chaired by Romney and filled with leaders from every part of the sector (plus other relevant experts).

The president would propose a new national goal: Instead of letting health care spending rise toward 20 percent or more of GDP in a decade, America should aim to reduce health spending by, say, 3 percent of GDP while maintaining or improving quality and outcomes.

Romney’s commission would have three deliverables. It would explain in detail the sources of difference between our outsize spending, the OECD nations’ average and Singapore’s; identify the major lessons and best practices on how others achieve more cost-effective systems of care; and identify options and scenarios that could move us toward these international benchmarks.

The potential impact on every sector of the provider community would be laid out.

One more thing: While acknowledging the perspective each commissioner brings given his or her professional role, Obama and Romney together would ask them to step beyond parochial concerns to address these questions in the context of the broader national interest. Seriously.

This can be tweaked, but you get the idea. Done right — and by experience and temperament, Mitt Romney is arguably better positioned than anyone in the country to lead such an effort — the Romney Report could transform the debate.

Over to you, alpha-male lunch buddies.

Matt Miller, a senior fellow at the Center for American Progress and co-host of public radio’s “Left, Right & Center,” writes a weekly online column for The Washington Post.