Market Risk, Interest Rate Risk, and Interdependencies in Insurer Stock Returns: A System-GARCH Model

We examine market risk, interest rate risk, and interdependencies in returns and return volatilities across three insurer segments within a System-GARCH framework. Three main results are obtained: market risk is greatest for accident and health (A&H) insurers, followed by life (Life) and property and casualty (P&C) insurers; interest rate sensitivity is negative and greatest for Life insurers; and interdependencies in returns are significant with the magnitude being strongest between P&C and A&H insurers. The implication is that greatest diversification benefits arise between Life and the other segments of the insurance industry. Market risk and interest rate risk for diversified firms are smaller than those for nondiversified firms for both product and geographic diversification.