Four years ago, I wrote a piece for Forbes called “This New Libor ‘Scandal’ Will Cause A Terrifying Financial Crisis,” in which I explained that the “real” Libor scandal wasn’t the Libor rigging scandal, but the fact that that Libor interest rates were simply too low for too long, which was helping to fuel dangerous economic bubbles around the world. I was frustrated that, despite all the attention the Libor rigging scandal had received, that almost nobody was paying attention to the even larger crisis that was looming. It’s not that I was trying to minimize or trivialize the Libor rigging scandal; it’s just that I believed that the mainstream financial world was missing the forest for the trees. As I explained, the Libor rigging scandal caused tens of billions of dollars worth of losses, but the eventual popping of global bubbles that formed as a result of ultra-low Libor rates would gut the global economy by trillions of dollars. I still firmly believe that.

“Libor” is an acronym that stands for “London Interbank Offered Rate,” which is an important benchmark interest rate that is used to price loans across the globe. As I explained in 2014:

As the world’s most important benchmark interest rate, approximately $10 trillion worth of loans and $350 trillion worth of derivatives use the Libor as a reference rate. Libor-based corporate loans are very prevalent in emerging economies, which is helping to inflate the emerging markets bubble that I am warning about. In Asia, for example, Libor is used as the reference rate for nearly two-thirds of all large-scale corporate borrowings. Considering this fact, it is no surprise that credit and asset bubbles are ballooning throughout Asia, as my report on Southeast Asia’s bubble has shown.

Like other benchmark interest rates, when the Libor is low, it means that loans are inexpensive, and vice versa. As with the U.S. Fed Funds Rate, Libor rates were cut to record low levels during the 2008-2009 financial crisis in order to encourage more borrowing and concomitant economic growth. Unfortunately, economic booms that are created via central bank manipulation of borrowing costs are typically temporary bubble booms rather than sustainable, organic economic booms. When central banks raise borrowing costs as an economic cycle matures, the growth-driving bubbles pop, leading to a bear market, financial crisis, and recession.