From time to time, we witness significant fluctuations in long-term interest rates, impacting the debt financing costs of governments and the monthly mortgage payments of homebuyers. These movements are influenced by various factors, one of which is the term premium. In this article, we will delve into the concept of the term premium, explore different methods of measuring it, and shed light on the limitations of our current knowledge.
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What Exactly is the Term Premium?
In simple terms, the term premium represents the additional yield that investors expect when holding a long-term bond instead of a series of shorter-term bonds. Let’s say the interest rate on the 10-year U.S. Treasury note is approximately 5.5%, while the interest rate on the 1-year U.S. Treasury bill is projected to average about 5% over the next 10 years. In this case, the term premium on the 10-year Treasury note would be around 0.5% or 50 basis points.
Investor expectations regarding the future direction of short-term interest rates significantly influence the term premium. For instance, in the example above, the term premium on the 10-year Treasury note depends on forecasts about shorter-term U.S. interest rates over a lengthy period, spanning ten years. However, it’s important to note that the term premium can be positive or negative, depending on the circumstances.
Different Approaches to Measuring the Term Premium
Measuring the term premium is no easy task. It involves obtaining data on or estimating financial markets’ expectations about the future trajectory of short-term interest rates over an extended period. Here, we will highlight four common methods of measurement:
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Survey-based measure: This approach involves surveying financial market participants to gather their predictions for future short-term interest rates. The data collected are then incorporated into the definition of the term premium. However, these surveys suffer from infrequent updates, rounding errors, and other issues. The Blue Chip Survey of forecasters, conducted semiannually, is one example of a survey-based measure.
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VAR-based measure: Instead of relying solely on surveys, economists employ macroeconomic forecasting models, such as vector autoregression (VAR), to predict short-term interest rates. Plugging these VAR-based forecasts into the term premium definition provides an alternative and more timely measure.
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RW model-based measure: Another method involves using a New Keynesian macroeconomic model, like the RW (Rudebusch and Wu) model, to forecast interest rates. This model allows for variations in the market’s long-run expected rate of inflation, providing valuable insights into long-term interest rate movements.
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Cochrane-Piazzesi measure: Cochrane and Piazzesi developed a purely empirical measure of the expected excess total return on long-term Treasury securities over the next year. By iterating these expected returns for each of the next ten years, economists can derive a measure of the 10-year term premium.
These methods represent just a few approaches to measure market expectations and the term premium. Each approach has its strengths and weaknesses, leading to variations in the estimated term premiums.
Limitations of Measuring the Term Premium
While there are several similarities among the different measures presented earlier, they also exhibit significant differences. Firstly, three out of the four measures display substantial long-term declines, while one measure (the Rudebusch-Wu model) shows a much smaller decrease. This implies that the RW model attributes most of the decline in long-term interest rates to market expectations for inflation and future short-term interest rates, rather than a decrease in the term premium.
Secondly, the term premium estimates in June 2007, the most recent data available, range from -2% to 2%. Even the survey and VAR measures, which typically align with each other, differ by approximately 50 basis points. This lack of consensus highlights the uncertainty surrounding the current level of the term premium.
Lastly, the Survey, VAR, and Cochrane-Piazzesi measures showcase significant short-term fluctuations, while the Rudebusch-Wu measure appears smoother over time. The RW model attributes changes in long-term bond yields to fluctuations in market expectations about long-run inflation and the future path of short-term interest rates, while the other measures tend to attribute these movements to changes in the term premium.
These discrepancies arise due to the challenges associated with measuring the term premium accurately. Market expectations of inflation and short-term interest rates over an extended period are difficult to ascertain, resulting in uncertainties surrounding the current term premium level.
In Conclusion
Long-term interest rates experience substantial fluctuations, partly driven by changes in the term premium. While many analysts attribute a significant portion of these changes to fluctuations in the term premium, accurately measuring it remains a challenge. However, ongoing research, better surveys, and advancements in econometric techniques offer hope for improving our understanding of the term premium and its impact on long-term interest rates.
