Those feeling bullish about the U.S. economy have lots to justify their optimism. The stock market and job creation are high, and unemployment and interest rates are low. The nation has logged more than a decade of aggregate growth since the 2008 Great Recession, with January marking 127 straight months of expansion, a historic milestone.

But new research from Harvard Business School sees trouble ahead. Unlike in past periods of sustained growth, America has “squandered” the opportunity presented by the recovery to address structural shortcomings in the economy and inequities in the culture ahead of the inevitable cyclical downturn, said Jan W. Rivkin, C. Roland Christensen Professor of Business Administration at HBS.

A survey of HBS alumni found many “quite worried” about the country’s future and its continued ability to compete in the global marketplace. Nearly half (48 percent) expected the trajectory for American firms and workers to decline over the next three years, according to the latest findings from the U.S. Competitiveness Project. Fewer than a third (31 percent) believe things will improve for either firms or workers.

Several factors contribute to this pessimism. In past expansions, leaders worked to reduce debt and increase financial stability. They placed a premium on enhancing the business environment through investing in public-good projects — education, infrastructure, and health care — and creating policies to enhance productivity. And they took steps to make the nation more compassionate and just. Today’s leaders, by comparison, “have done nothing” about these issues, according to the report.

Since 2011, the U.S. Competitiveness Project has surveyed HBS alumni every few years to better understand how business leaders see the trendlines of American competitiveness in the global marketplace in an effort to shore up its perceived strengths and weaknesses.

The real underlying problem, the latest report found, is a political one, which will not be resolved simply by electing new leaders. Partisan gridlock has indeed worsened in recent years, but it has been with us over several administrations, hampering the nation’s ability to craft solutions to complex economic and cultural problems at home and abroad.

“Most disturbing” is that much like the political divisions within society overall, the partisanship and “deep dysfunction” of our political system are distorting how the world appears to people. HBS alumni don’t just disagree about where the country is headed anymore, they lack “a shared reality,” the report found.

Perceptions of the nation’s economic strengths and weaknesses closely align not with the sector they work in or where they live or even their age, but with which political party they support, a major shift since the project’s last survey in 2016. Republicans (51 percent) were far more optimistic about the nation’s competitive outlook in the next three years than were Democrats (24 percent).