Andrew Park, senior policy analyst for hedge funds and private equity at Americans for Financial Reform and the author of the report, estimates the volume of leveraged loans and high-yield debt outstanding has roughly doubled since 2008, while the volume of direct-lending debt has increased from virtually zero to an estimate of more than $1 trillion. “The fact is that there is no good way to understand how indebted companies actually are,” [Mr. Park] said. “We have guesses and estimates based on the data out there, but there is no standardized way to look at it.”