$500 billion in aid to small businesses: How much did it help?

As Democrats and Republicans spent months last fall arguing over how to rescue the economy, one provision drew widespread support from lawmakers: reviving the Paycheck Protection Program, the government’s marquee effort to help small businesses weather the pandemic.

The Senate Republican leader, Mitch McConnell of Kentucky, called the lending program “a bipartisan slam dunk.” House Democrats included an extension and expansion of the program in aid packages in the summer and the fall. And Treasury economists said in December that the program might have saved nearly 19 million jobs.

Yet there is dissent from one notable contingent: Academic economists who have studied the program have concluded that it has saved relatively few jobs and that, at a cost of more than half a trillion dollars, it has been far less efficient than other government efforts to help the economy.

“A very large chunk of the benefit went to a very small share of the firms, and those were probably the firms least in need,” said David Autor, an M.I.T. economist who led one study.

The divergence in views over the program’s economic payoff stems in part from ambiguity about its goals: saving jobs or saving businesses.

Using different methodology than the Treasury economists, Mr. Autor says the Paycheck Protection Program saved 1.4 million to 3.2 million jobs. Other researchers have offered broadly similar estimates.

Given the program’s cost, saving jobs on that scale doesn’t necessarily qualify as a success. Unemployment benefits also provide income, at far less expense, and programs like food assistance and aid to state and local governments pack a larger economic punch, according to many assessments.

And because the paycheck program was designed to reach as many businesses as possible, much of the money went to companies that were at little risk of laying off workers, or that would have brought them back quickly even without the help.

Many policy experts on Wall Street and in Washington — as well as businesses and banks on Main Streets across the country — say the program’s merits should be assessed instead on what it did to save businesses. On that basis, they say, it helped prevent a greater calamity and fostered economic healing.