Overreaction to Fearsome Risks

Fearsome risks are those that stimulate strong emotional responses. Such risks, which usually involve high consequences, tend to have low probabilities, since life today is no longer nasty, brutish and short. In the face of a low-probability fearsome risk, people often exaggerate the benefits of preventive, risk-reducing, or ameliorative measures. In both personal life and politics, the result is damaging overreactions to risks. We offer evidence for the phenomenon of probability neglect, failing to distinguish between high and low-probability risks. Action bias is a likely result.

Price versus Quantity: Market Clearing Mechanisms When Sellers Differ in Quality

High-quality producers in a vertically differentiated market can reap superior profits by charging higher prices, selling greater quantities, or both. If qualities are known by consumers and production costs are constant, then having a higher quality secures the producer both higher price and higher quantity; if marginal costs are rising, having a higher quality assures only higher price. If only some consumers can discern quality but others cannot, then high- and low-quality producers may set a common price, but the high-quality producer will sell more. In this context, quality begets quantity. Empirical analyses suggest that in both the mutual fund and automobile industries, high-quality producers sell more units than their low-quality competitors, but at no higher price (or markup) per unit.

Collective Investment Decision Making with Heterogeneous Time Preferences

We examine the investment decision problem of a group whose members have heterogeneous time preferences. In particular, they have different discount factors for utility, possibly not exponential. We characterize the properties of efficient allocations of resources and of shadow prices that would decentralize such allocations. We show in particular that the term structure of interest rates is decreasing when all members have DARA preferences. Heterogeneous groups should not use exponential discounting for their collective investment decisions even if all agents discount exponentially. We also exhibit conditions that lead the representative agent to have a rate of impatience that decreases with GDP per capita.

Treasury Bill Futures as Hedges Against Inflation Risk

An important risk facing agents in a monetary economy arises from inflation uncertainty: in the U.S. for the 1953-84 period, unexpected quarterly inflation had a standard deviation of 2.1%. The costs of such uncertainty are likely to be even higher for multi-year contracts, since we estimate that a 1% unexpected inflation this year implies an upward revision of 0.43% for expected inflation for the forthcoming year and 1% for the years beyond that. The prospect of hedging inflation risk exposure using conventional financial instruments is bleak, as has been widely documented. We develop a theoretical case for Treasury bill futures as a inflation risk hedge by jointly assuming that (1) the Fisher Hypothesis applies to Treasury bill yields, (2) the Unbiased Expectations Hypothesis (UEH) applies to futures prices, and (3) inflation is an autoregressive process. Our empirical analysis shows that Treasury bill futures can reduce single-period inflation risk by about 30-40%. The expected cost of using such futures is close to zero, since we find that the Unbiased Expectations Hypothesis for Treasury bill futures cannot be rejected. Our results provide new indirect support for the Fisher Hypothesis.

Generic Scrip Share and the Price of Brand-Name Drugs: The Role of the Consumer

Generic drug utilization has risen dramatically, from 19% of scrips in 1984 to 47% in 2001, thus bringing significant direct dollar savings. Generic drug use may also yield indirect savings if it lowers the average price of those brand-name drugs that are still purchased. Prior work indicates - and we confirm - that generic competition does not induce brand-name producers to lower prices. However, consumer choices between generic and brand-name drugs could affect the average price of those brand-name drugs that are purchased. We use nationally representative panel data on drug utilization and costs for the years 1996-2001 to examine how the share of an individual's prescriptions filled by generics affects his average out-of-pocket cost for brand-name drugs. Our principal finding is that a higher generic scrip share lowers average brand-name prices to consumers, presumably because consumers are more likely to substitute generics when the price gap is great. This effect is substantial: a 10% increase in the consumer's generic scrip share is associated with a 15.6% decline in the average price he pays for brand-name drugs.

The Behavior of Savings and Asset Prices When Preferences and Beliefs Are Heterogeneous

Movements in asset prices are a major risk confronting individuals. This paper establishes new asset pricing results when agents differ in risk preference, time preference and/or expectations. It shows that risk tolerance is a critical concept driving savings decisions, consumption allocations, prices and return volatilities. Surprisingly, due to the equilibrium risk sharing, the precautionary savings motive in the aggregate can vastly exceed that of even the most prudent actual agent in the economy. Consequently, a low real interest rate, resulting from large aggregate savings, can prevail with reasonable risk aversions for all agents. One downside of a large aggregate savings motive is that savings rates become extremely sensitive to output fluctuation. Thus, the same mechanism that produces realistically low interest rates tends to make them unrealistically volatile. A powerful isomorphism allows differences in time preference and expectations to be swept away in the analysis, yielding an equivalent economy whose agents differ merely in risk aversion. These results hold great potential to simplify the analysis of heterogeneous-agent economies, as we demonstrate in quantifying how asset prices move and bounding their volatilities. All results are obtained in closed form for any number of agents possessing additively separable preferences in an endowment economy.

Trust and the Reference Point for Trustworthiness in Gulf and Western Countries

Why is private investment so low in Gulf compared to Western countries? We investigate cross-regional differences in trust and reference points for trustworthiness as possible factors. Experiments controlling for cross-regional differences in institutions and beliefs about trustworthiness reveal that Gulf citizens pay much more than Westerners to avoid trusting, and hardly respond when returns to trusting change. These differences can be explained by subjects' gain/loss utility relative to their region's reference point for trustworthiness. The relation-based production of trust in the Gulf induces higher levels of trustworthiness, albeit within groups, than the rule-based interactions prevalent in the West.