Yield Curve and Predicted GDP Growth, December 2018
Covering November 24–December 14, 2018
|3-month Treasury bill rate (percent)||2.42||2.40||2.31|
|10-year Treasury bond rate (percent)||2.89||3.06||3.18|
|Yield curve slope (basis points)||47||66||87|
|Prediction for GDP growth (percent)||2.0||2.0||2.0|
|Probability of recession in 1 year (percent)||24.0||20.3||16.6|
Overview of the Latest Yield Curve Figures
The short days and long nights of December have seen the yield curve twist flatter, with short rates edging up and long rates falling. The 3-month (constant maturity) Treasury bill rate rose to 2.42 percent (for the week ending December 14), up from November’s 2.40 percent and from October’s 2.31 percent. The 10-year rate (also constant maturity) moved in the opposite direction, falling to 2.89 percent, dropping down from November’s 3.06 percent and from October’s 3.18 percent, and crossing the 3-percent level. The twist brought the slope down to 47 basis points, below November’s 66 basis points, and down two-fifths of a percent from October’s slope of 87 basis points.
Despite a flatter yield curve, expectations of growth stayed the same, as the model incorporated the string of strong GDP growth numbers in recent quarters. Using past values of the spread and GDP growth suggests that real GDP will grow at about a 2.0 percent rate during the next year, which is even with the predicted rates in October and November. Although the time horizons do not match exactly, the forecast, like other forecasts, does show moderate growth.
While the flatter yield curve did not reduce expectations of growth, it did increase the estimated probability of recession. Using the yield curve to predict whether the economy will be in recession in the future, we estimate the expected chance of the economy being in a recession next December at 24.0 percent, up from November’s number of 20.3 percent, which was above October’s estimate of 16.6 percent. So while the yield curve is optimistic about the recovery continuing, it does show some tail risk of a recession in the future.
The Yield Curve as a Predictor of Economic Growth
The slope of the yield curve—the difference between the yields on short- and long-term maturity bonds—has achieved some notoriety as a simple forecaster of economic growth. The rule of thumb is that an inverted yield curve (short rates above long rates) indicates a recession in about a year, and yield curve inversions have preceded each of the last seven recessions (as defined by the NBER). Preceding the Great Recession, the yield curve inverted in August 2006, a bit more than a year before the recession took hold in December 2007. There have been two notable false positives: an inversion in late 1966 and a very flat curve in late 1998.
More generally, a flat curve indicates weak growth and, conversely, a steep curve indicates strong growth. One measure of slope, the spread between ten-year Treasury bonds and three-month Treasury bills, bears out this relation, particularly when real GDP growth is lagged a year to line up growth with the spread that predicts it.
Predicting GDP Growth
We use past values of the yield spread and GDP growth to project what real GDP will be in the future. We typically calculate and post the prediction for real GDP growth one year forward.
Predicting the Probability of Recession
While we can use the yield curve to predict whether future GDP growth will be above or below average, it does not do so well in predicting an actual number, especially in the case of recessions. Alternatively, we can employ features of the yield curve to predict whether or not the economy will be in a recession at a given point in the future. Typically, we calculate and post the probability of recession one year forward.
Of course, it might not be advisable to take these numbers quite so literally, for two reasons. First, this probability is itself subject to error, as is the case with all statistical estimates. Second, other researchers have postulated that the underlying determinants of the yield spread today are materially different from the determinants that generated yield spreads during prior decades. (For a recent example, see “Recessions Probabilities.”) Differences could arise from changes in international capital flows and inflation expectations, for example. The bottom line is that yield curves contain important information for business cycle analysis, but, like other indicators, should be interpreted with caution. For more detail on these and other issues related to using the yield curve to predict recessions, see the Commentary “Does the Yield Curve Signal Recession?” Our friends at the Federal Reserve Bank of New York also maintain a website with much useful information on the topic, including their own estimate of recession probabilities.