In theory, the American economy is doing well. Unemployment is at the lowest level in this century; corporations are investing, and there are signs of increasing consumer spending. Fine. However, there are also reasons to be concerned. One is the “flattening of the yield curve.”
The United States government borrows money by selling bonds (Treasury notes). Basically, bonds are IOUs + Interest. These Treasury notes run for different periods of time and pay different rates of interest. Long-term bonds run for like 10 years, while short-term bonds run for like 2 years. The long-term bonds pay higher interest (called “yield”) than do short-term bonds to account for inflation. When the economy is growing strongly, prices will tend to rise. The gap between the yield for long-term bonds and the yield for short-term bonds is called the “yield curve.”
If people think the economy will grow, then they will put their money in stocks and the Treasury will have to pay higher interest on its long-term bonds. If a lot of people want the security of long-term bonds, rather than the risk of stocks and don’t fear inflation, then the Treasury won’t have to pay as much interest.
Then there are the banks. They borrow money at low short-term rates and lend it at higher long-term rates. That’s how they make a profit. If short-term rate approach long-term rates, it pinches their profits. If short-term rates exceed long-term rates, they actually lose money. So, they stop borrowing and lending.
Here’s the thing. The gap between long-term and short-term bonds has been closing. This is called “the yield curve flattening.” A year ago the gap was 1 percent; three months ago it was 0.5 percent; in early July it fell below 0.3 percent. Interest rates for long-term bonds has not been rising much, while the rates for short-term bonds has continued to rise. This suggests that bond-traders do not expect a lot of inflation, which suggests that they have doubts about future economic growth. At some point, the yield for short-term bonds could rise above the yield for long-term bonds. When this happens, the yield curve is said to be “inverted.” Economists interpret an inverted yield curve as “a powerful signal of recession.” Inversions have come before every recession and one near-recession since 1955. However, the time lag between an inversion and a recession can stretch from six months to two years. So, we aren’t there yet.
The huge number of bonds that central banks acquired to push down long-term rates during the period of “quantitative easing” are continuing to weigh on the long-term rates. Now the Federal Reserve Bank is raising short-term rates to prevent excessive price rises in a strong economy. There is mounting concern that policies being pursued by the Federal Reserve Bank could harm the economy by pinching off lending or by pushing banks to pursue riskier strategies. On the other hand, there is evidence that, in the wake of the “Great Recession,” the yield curve has lost some of its predictive power. Moreover, a strong American economy coupled with a slowing world economy could push foreigners to buy long-term bonds. The issue at hand is whether the Fed should continue to raise short-term interest rates as planned. The stakes are high.
 Matt Philips, “A Recession Signal Is Flashing Yellow,” NYT, 27 June 2018.
 Nick Timiraos, “Fed Debates Signal From Yield Curve,” WSJ, 9 July 2018.