Corporations, like people, are pretty simple: They do what they are rewarded to do. So when the Federal Reserve, by keeping interest rates very low for nearly a decade, rewards companies for borrowing money by making it historically inexpensive to do so, it can’t be a surprise to anyone that that’s exactly what they did.
In 2008, in the wake of the financial crisis, the Fed began its “quantitative easing” program, a determined effort to buoy the economy by lowering the cost of borrowing. It bought up trillions of dollars in Treasury and other debt securities, effectively reducing long-term interest rates.