As worries rise over the outlook for global growth, excessive debt levels are drawing the eyes of nervous investors worried that more countries will struggle to shoulder their debts.

Adam Slater, lead economist for Oxford Economics, says the risks from the growing buildup of credit across the globe is worse than in previous years, with the dangers chiefly emanating from corporations that took advantage of low interest rates to borrow heavily.

“Overall, credit vulnerabilities look greater than when we last looked in 2017; the corporate credit channel in particular could worsen a global economic slowdown,” he said, in a Monday note.

The global economy has failed to keep up with the ramp-up in credit growth. The International Monetary Fund trimmed its global economic forecast for 2019 to 3.5% from its previous expectation of 3.7%, while it estimated the global expansion in 2018 had proceeded at a rate of 3.7% down from 3.9%.

Global growth concerns have taken a toll on financial markets, contributing to the U.S. stock market’s December slide. Stocks have bounced back sharply, with the S&P 500 SPX, -1.11% rising 13% from its Christmas Eve low through Friday. Worries about global growth were seen contributing to a weaker tone on Tuesday, however, with the S&P 500 down 1.1% and the Dow Jones Industrial Average DJIA, -0.87% declining around 250 points.

The one-two punch of a slower economy and tightening financial conditions could result in a feedback loop as companies dependent on credit cut back on spending or even fall into bankruptcy, dampening growth further.

“An intensification of the recent growth slowdown and further drops in asset prices…could also trigger a negative ‘financial accelerator’ effect with higher debt defaults, tighter bank lending conditions and more cautious behavior by firms,” said Slater.

According to his analysis, the primary contributor to the rising tide of global debt was corporate lending growth in countries like China, France and Canada, and not so much from households. Global household debt levels have remained relatively stable since 2008.

Market participants have mainly focused on weaknesses in U.S. corporate credit even though the ratio of its corporate debt to gross domestic product, a rough gauge of an economy’s ability to service its debts, has increased by less than 10 percentage points over the past five years, a slower pace of growth than economies like Hong Kong, China, France, Canada and Chile.

Yet, Slater says a swath of U.S. corporate bonds have seen their credit ratings slashed to the lowest investment-grade rung. While, the cash hoards buoying U.S. corporations are shared among a select few, creating a rosier picture in the U.S. than individual balance sheets would show.

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The increased attention to the growth risks from elevated debt levels may tempt investors to draw analogies with 2008 when the global financial system was brought to its heels after investors discovered banks, leveraged to the hilt, were harboring large stockpiles of toxic assets.

But Slater says a better comparison would be the years between 2001 and 2002, when an overhang of excessive corporate debt weighed on the global economy’s prospects. Those turbulent years also saw a culmination of several emerging market debt crises in Turkey and Argentina.