Question: Explain theory of Market Segmentation theory related to term structure of interest rate and describe the implications for the shape of yield curve.

Market segmentation theory is a theory that long and short-term interest rates are not related to each other. It also states that the prevailing interest rates for short, intermediate, and long-term bonds should be viewed separately like items in different markets for debt securities. It is based on the belief that the market for each segment of bond maturities consists mainly of investors who have a preference for investing in securities with specific durations: short, intermediate, or long-term.

This theory's major conclusions are that yield curves are determined by supply and demand forces within each market/category of debt security maturities and that the yields for one category of maturities cannot be used to predict the yields for a different category of maturities.

Market segmentation theory further asserts that the buyers and sellers who make up the market for short-term securities have different characteristics and motivations than buyers and sellers of intermediate and long-term maturity securities. The theory is partially based on the investment habits of different types of institutional investors, such as banks and insurance companies. Banks generally favor short-term securities, while insurance companies generally favor long-term securities.

Implications for the shape of Yield Curve

The yield curve is a direct result of the market segmentation theory. Yield curve is a line that plots yields (interest rates) of bonds having equal credit quality but differing maturity dates. The slope of the yield curve gives an idea of future interest rate changes and economic activity. There are three main types of yield curve shapes: normal (upward sloping curve), inverted (downward sloping curve) and flat.

Normal Yield Curve

A normal or up-sloped yield curve indicates yields on longer-term bonds may continue to rise, responding to periods of economic expansion. When investors expect longer-maturity bond yields to become even higher in the future, many would temporarily park their funds in shorter-term securities in hopes of purchasing longer-term bonds later for higher yields.

In a rising interest rate environment, it is risky to have investments tied up in longer-term bonds when their value has yet to decline as a result of higher yields over time. The increasing temporary demand for shorter-term securities pushes their yields even lower, setting in motion a steeper up-sloped normal yield curve.

Inverted Yield Curve

An inverted or down-sloped yield curve suggests yields on longer-term bonds may continue to fall, corresponding to periods of economic recession. When investors expect longer-maturity bond yields to become even lower in the future, many would purchase longer-maturity bonds to lock in yields before they decrease further.

The increasing onset of demand for longer-maturity bonds and the lack of demand for shorter-term securities lead to higher prices but lower yields on longer-maturity bonds, and lower prices but higher yields on shorter-term securities, further inverting a down-sloped yield curve.

Flat Yield Curve

A flat yield curve may arise from the normal or inverted yield curve, depending on changing economic conditions. When the economy is transitioning from expansion to slower development and even recession, yields on longer-maturity bonds tend to fall and yields on shorter-term securities likely rise, inverting a normal yield curve into a flat yield curve.

When the economy is transitioning from recession to recovery and potential expansion, yields on longer-maturity bonds are set to rise and yields on shorter-maturity securities are sure to fall, tilting an inverted yield curve toward a flat yield curve.