Expectations and liquidity premium
Pure expectations theory, traced to Irving Fisher, says a long-term rate equals the average of expected future short-term rates, so an upward-sloping yield curve means markets expect rates to rise. On its own it can't explain why the curve usually slopes up. Liquidity premium theory (Hicks) adds a premium investors demand for the extra price risk of long bonds.
Segmentation and the synthesis
Market segmentation theory (Culbertson) treats each maturity as its own market with its own supply and demand. Preferred habitat theory splits the difference: investors favor certain maturities but will switch for enough extra yield. Textbooks like Mishkin's conclude the liquidity premium/preferred habitat view best fits the facts—rates move together, and curves usually slope up.
FAQ
- What does a flat curve mean under expectations theory?
- That markets expect short-term rates to stay unchanged.
- Which theory fits the data best?
- Liquidity premium (preferred habitat) theory, which combines expectations with a term premium.
Sources reviewed: 2026-10-26
References
- Fisher, I. (1896). Appreciation and Interest. American Economic Association.
- Hicks, J. R. (1939). Value and Capital. Oxford: Clarendon Press.
- Culbertson, J. M. (1957). The term structure of interest rates. Quarterly Journal of Economics, 71(4), 485–517.
- Mishkin, F. S. (2019). The Economics of Money, Banking, and Financial Markets (12th ed.). Pearson.