(Bloomberg) -- Former Treasury Secretary Lawrence Summers said the Trump administration’s looming tariff hikes are set to impose an oil crisis-like shock to the economy that shrinks its productive capacity — boosting both prices and unemployment.

“This is the kind of thing you discuss in the way we would usually discuss an oil-price spike or earthquake or a drought, as a supply shock,” Summers said on Bloomberg Television’s Wall Street Week with David Westin. “The question is mostly how much damage is going to be done.”

Summers spoke hours before President Donald Trump is scheduled to unveil so-called reciprocal tariffs against US trading partners. Those will add to the list of levies he’s already announced, including 25% duties on steel and aluminum imports, a cumulative 20% surtax on Chinese goods and up to 25% tariffs on a range of Canadian and Mexican products.

“These are very consequential economic policies,” with implications for foreign relations and national security as well, said Summers, a Harvard University professor and paid contributor to Bloomberg TV.

The “proximate” effect will be to boost prices, with effects then rippling out to include less employment and reduced investment, he said. “This is a classic supply shock” that puts the Federal Reserve “in a very difficult position.”

Bad ‘Mercantilism’

Summers cited past analysis of tariff increases in the first Trump administration that showed nearly a “dollar for dollar” impact on prices faced by US consumers.

The former Treasury chief, who served in a Clinton administration that struck trade deals with China and other countries and for a time threatened tariff hikes on Japan, also criticized Trump’s particular form of protectionism.

By imposing increased duties on steel and aluminum, the administration is raising the prices of vital inputs for industries that use those commodities, Summers noted. “You’re reducing the competitiveness of the producers” in that process.

“It’s not even good mercantalism,” Summers said of the Trump approach.