During his tenure in the White House, President Obama pushed to address income stagnation by shifting more of the tax burden from the middle class to the rich and expanding public programs like universal health insurance.

Both strategies are now targeted by President-elect Donald J. Trump and Republicans in Congress, led by House Speaker Paul Ryan. Like many conservatives, Mr. Ryan argues that aid to the poor is ultimately counterproductive because it undermines the incentive to work. Proposals put forward by Republican leaders, though short on details, make clear that they want to roll back benefits like Medicaid and the Affordable Care Act, which primarily help the poor, and direct the largest tax cuts to the wealthiest Americans.

About 30 percent of the country’s income is channeled to federal, state and local taxes. Apart from military spending and performing basic public services, much of that is distributed back to individuals through various programs and tax benefits in the form of Social Security checks, Medicare benefits and veterans’ benefits. But until now, no one has truly measured the full impact that tax payments, government spending, noncash benefits and nontaxable income together have on inequality.

Abundant documentation of income inequality already exists, but it has been challenged as incomplete. Studies have excluded the impact of taxes and value of public benefits, skeptics complained, or failed to account for the smaller size of households over time.

This latest project tries to address those earlier criticisms. What the trio of economists found is that the spectacular growth in incomes at the peak has so outpaced the small increase at the bottom from public programs intended to ameliorate poverty and inequality that the gap between the wealthiest and everyone else has continued to widen.

Average incomes, adjusted for inflation, grew by 61 percent from 1980 to 2014. But nearly $7 out of every additional $10 went to those in the top tenth of the income scale.