Michael Rothschild

Bio: Michael Rothschild is an academic researcher from University of Wisconsin-Madison. The author has contributed to research in topics: Arbitrage pricing theory & Diversification (finance). The author has an hindex of 49, co-authored 93 publications receiving 20102 citations. Previous affiliations of Michael Rothschild include Harvard University & University of California, San Diego.

Equilibrium in Competitive Insurance Markets: An Essay on the Economics of Imperfect Information

Abstract: Economic theorists traditionally banish discussions of information to footnotes. Serious consideration of costs of communication, imperfect knowledge, and the like would, it is believed, complicate without informing. This paper, which analyzes competitive markets in which the characteristics of the commodities exchanged are not fully known to at least one of the parties to the transaction, suggests that this comforting myth is false. Some of the most important conclusions of economic theory are not robust to considerations of imperfect information.

Arbitrage, Factor Structure, and Mean-Variance Analysis on Large Asset Markets

Abstract: We examine the implications of arbitrage in a market with many assets. The absence of arbitrage opportunities implies that the linear functionals that give the mean and cost of a portfolio are continuous; hence there exist unique portfolios that represent these functionals. These portfolios span the mean-variance efficient set. We resolve the question of when a market with many assets permits so much diversification that risk-free investment opportunities are available. Ross 112, 141 showed that if there is a factor structure, then the mean returns are approximately linear functions of factor loadings. We define an approximate factor structure and show that this weaker restriction is sufficient for Ross' result. If the covariance matrix of the asset returns has only K unbounded eigenvalues, then there is an approximate factor structure and it is unique. The corresponding K eigenvectors converge and play the role of factor loadings. Hence only a principal component analysis is needed in empirical work.

Arbitrage, Factor Structure, and Mean-Variance Analysis on Large Asset Markets

Abstract: We examine the implications of arbitrage in a market with many assets. The absence of arbitrage opportunities implies that the linear functionals that give the mean and cost of a portfolio are continuous; hence there exist unique portfolios that represent these functionals. These portfolios span the mean-variance efficient set. We resolve the question of when a market with many assets permits so much diversification that risk-free investment opportunities are available. Ross [12,14] showed that if there is a factor structure, then the mean returns are approximately linear functions of factor loadings. We define an approximate factor structure and show that this weaker restriction is sufficient for Ross' result. If the covariance matrix of the asset returns has only K unbounded eigenvalues, then there is an approximate factor structure and it is unique. The corresponding K eigenvectors converge and play the role of factor loadings. Hence only a principal component analysis is needed in empirical work.

Perceived usefulness, perceived ease of use, and user acceptance of information technology

Abstract: Valid measurement scales for predicting user acceptance of computers are in short supply. Most subjective measures used in practice are unvalidated, and their relationship to system usage is unknown. The present research develops and validates new scales for two specific variables, perceived usefulness and perceived ease of use, which are hypothesized to be fundamental determinants of user acceptance. Definitions of these two variables were used to develop scale items that were pretested for content validity and then tested for reliability and construct validity in two studies involving a total of 152 users and four application programs. The measures were refined and streamlined, resulting in two six-item scales with reliabilities of .98 for usefulness and .94 for ease of use. The scales exhibited hgih convergent, discriminant, and factorial validity. Perceived usefulness was significnatly correlated with both self-reported current usage r = .63, Study 1) and self-predicted future usage r = .85, Study 2). Perceived ease of use was also significantly correlated with current usage r = .45, Study 1) and future usage r = .59, Study 2). In both studies, usefulness had a signficnatly greater correaltion with usage behavior than did ease of use. Regression analyses suggest that perceived ease of use may actually be a causal antecdent to perceived usefulness, as opposed to a parallel, direct determinant of system usage. Implications are drawn for future research on user acceptance.

Exploration and Exploitation in Organizational Learning

Abstract: This paper considers the relation between the exploration of new possibilities and the exploitation of old certainties in organizational learning. It examines some complications in allocating resources between the two, particularly those introduced by the distribution of costs and benefits across time and space, and the effects of ecological interaction. Two general situations involving the development and use of knowledge in organizations are modeled. The first is the case of mutual learning between members of an organization and an organizational code. The second is the case of learning and competitive advantage in competition for primacy. The paper develops an argument that adaptive processes, by refining exploitation more rapidly than exploration, are likely to become effective in the short run but self-destructive in the long run. The possibility that certain common organizational practices ameliorate that tendency is assessed.

Credit Rationing in Markets with Imperfect Information.

Abstract: According to basic economics, if demand exceeds supply, prices will rise, thus decreasing demand or increasing supply until demand and supply are in equilibrium; thus if prices do their job, rationing will not exist. However, credit rationing does exist. This paper demonstrates that even in equilibrium, credit rationing will exist in a loan market. Credit rationing is defined as occurring either (a) among loan applicants who appear identical, and some do and do not receive loans, even though the rejected applicants would pay higher interest rates; or (b) there are groups who, with a given credit supply, cannot obtain loans at any rate, even though with larger credit supply they would. A model is developed to provide the first theoretical justification for true credit rationing. The amount of the loan and the amount of collateral demanded affect the behavior and distribution of borrowers. Consequently, faced with increased credit demand, it may not be profitable to raise interest rates or collateral; instead banks deny loans to borrowers who are observationally indistinguishable from those receiving loans. It is not argued that credit rationing always occurs, but that it occurs under plausible assumptions about lender and borrower behavior. In the model, interest rates serve as screening devices for evaluating risk. Interest rates change the behavior (serve as incentive mechanism) for the borrower, increasing the relative attractiveness of riskier projects; banks ration credit, rather than increase rates when there is excess demand. Banks are shown not to increase collateral as a means of allocating credit; although collateral may have incentivizing effects, it may have adverse selection effects. Equity, nonlinear payment schedules, and contingency contracts may be introduced and yet there still may be rationing. The law of supply and demand is thus a result generated by specific assumptions and is model specific; credit rationing does exist. (TNM)

On the pricing of corporate debt: the risk structure of interest rates

Abstract: Presented at the American Finance Association Meeting, New York, December 1973.(This abstract was borrowed from another version of this item.)