Americans blame political gridlock in Washington for the country’s declining economic competitiveness and hold both Democrats and Republicans responsible, a Harvard Business School study released on Wednesday found.

The study noted that U.S. gross domestic product grew at a rate of about 2% since 2000, well below the 3 to 4% average in the prior half-century. It said a range of factors including a complicated corporate tax code, tangled immigration system and aging roads contribute to the slow growth.

The study contends that factors including a growing wealth gap, declines in productivity growth and a rise in the number of working-age people neither employed nor seeking jobs show that the U.S. economy is becoming less competitive.

A majority of the school’s alumni surveyed said they believed the U.S. political system was hurting the economy. That view crossed party lines, with 82% of Republicans, 74% of independents, and 56% of Democrats agreeing.

“Only a minority of members of either party felt that their own party was acting in a way that supported economic growth,” said Jan Rivkin, a professor at Harvard Business School and co-author of the report.

The survey did not ask whether respondents preferred Republican presidential candidate Donald Trump or Democratic candidate Hillary Clinton.

Some respondents worry that neither candidate for the White House could overcome gridlock in Washington, Rivkin said, adding “Anyone elected into the current system would face pressure toward paralysis.”

A concurrent survey of the general public found smaller, but still significant, numbers blaming the political system for a languishing U.S. economy.

Some 49% of Republicans, 38% of independents, and 26% of Democrats at large said politics were hurting growth.

The study contends partisan gridlock is preventing the federal government from tackling structural problems facing the U.S. economy, and suggested steps to address that gridlock. Among them: Changing rules that allow lawmakers to “gerrymander” districts to ensure one party’s dominance; reforming campaign finance; setting term limits in the House and Senate, and eliminating party control of the federal legislative process.

The study comes a day after the Census Bureau reported median household income surged 5.2% last year to $56,500, its highest since 2007.

The surveys included responses from 4,807 alumni of Harvard Business School from May 3 through June 6 and 1,048 members of the general public polled June 10-26. The public survey had a margin of error of 3.3 percentage points, margin of error does not apply to the alumni survey as it was not a random sample.