Since the financial crisis, economists have been frustrated by their lack of influence in Washington.

From the profession, President Barack Obama recruited leftist ideologues. They concluded, for example, that boosting the minimum wage would increase the demand for semiskilled workers and raising the demand for health-care services would lower prices. The principle economist among the architects of the Affordable Care Act was happy to cynically dupe voters by hiding facts.

Liberal as universities may be, those views are hardly supported by what economics professors teach about supply and demand, but President Donald Trump has recruited even fewer dismal scientists to fashion his controversial trade and immigration policies.

Kevin Hassett and Peter Navarro are really the only economists with influence on policy, and they earned their academic chops on tax and management issues, not the World Trade Organization and regional trade agreements, nor migration and labor markets.

More broadly, though, the profession has no one to blame but itself for its lack of influence. For too long now, economists have ignored what standard economics textbooks actually say about free trade and labor mobility.

The theory of comparative advantage demonstrates international trade and specialization – Americans design iPhones, China assembles them – and should more efficiently use capital and labor and raise living standards. However, that conclusion is built on a pyramid of assumptions often not met in the real world – something economists are bound take into account when making policy prescriptions.

Comparative advantage assumes balanced trade and full employment but under the trade deals Trump inherited, America has a huge deficit. Unemployment is at 4%, but the share of adults employed or looking for work is still well below pre-financial crisis levels.

One-in-twenty working-age adults are now receiving Social Security disability pensions, and those are more heavily concentrated in Middle America where factories are shuttered, main streets boarded up, and opioid addiction rampant. Medicaid and food stamps are often effectively offered to adults without children who refuse to look for work.