The Cohen Macaulay property for noncommutative rings

Let R be a noetherian ring which is a finite module over its centre Z(R). This paper studies the consequences for R of the hypothesis that it is a maximal Cohen Macaulay Z(R)-module. Old results are reviewed and a number of new results are proved. The additional hypothesis of homological grade symmetry is proposed as the appropriate extra lever needed to extend the classical commutative homological hierarchy to this setting, and results are given offering evidence in support of this proposal.Comment: Preliminary version; comments welcom

Competing Dimensions of Energy Security: An International Perspective

How well are industrialized nations doing in terms of their energy security? Without a standardized set of metrics, it is difficult to determine the extent that countries are properly responding to the emerging energy security challenges related to climate change, growing dependence on fossil fuels, population growth and economic development. In response, we propose the creation of an Energy Security Index to inform policymakers, investors and analysts about the status of energy conditions. Using the United States and 21 other member countries of the Organization for Economic Cooperation and Development (OECD) as an example, and looking at energy security from 1970 to 2007, our index shows that only four countries¡ªBelgium, Denmark, Japan, and the United Kingdom¡ªhave made progress on multiple dimensions of the energy security problem. The remaining 18 have either made no improvement or are less secure. To make this argument, the first section of the article surveys the scholarly literature on energy security from 2003 to 2008 and argues that an index should address accessibility, affordability, efficiency, and environmental stewardship. Because each of these four components is multidimensional, the second section discusses ten metrics that comprise an Energy Security Index: oil import dependence, percentage of alternative transport fuels, on-road fuel economy for passenger vehicles, energy intensity, natural gas import dependence, electricity prices, gasoline prices, sulfur dioxide emissions, and carbon dioxide emissions. The third section analyzes the relative performance of four countries: Denmark (the top performer), Japan (which performed well), the United States (which performed poorly), and Spain (the worst performer). The article concludes by offering implications for policy. Conflicts between energy security criteria mean that advancement along any one dimension can undermine progress on another dimension. By focusing on a 10-point index, public policy can better illuminate such tradeoffs and can identify compensating policies

Educational Attainment and Risk Preference

We explore the relationship between risk preference and educational attainment for a sample of adults drawn from the 1996 U.S. Panel Study of Income Dynamics (PSID). Using a sequence of questions from the 1996 PSID, we construct measures of an individual´s risk aversion and risk tolerance allowing us to explore the implications of interpersonal differences in risk preference for educational attainment. Our empirical findings suggest that an individual´s degree of risk aversion (tolerance) is inversely (positively) associated with their educational attainment. In addition, using the 1997 and 2002 Child Development Supplements of the PSID, we explore the relationship between the risk preference of parents and the academic achievements of their children. Our findings suggest that a parent´s degree of risk aversion (tolerance) is negatively (positively) related to the academic achievements of their children

Educational loans and attitudes towards risk

We explore the relationship between willingness to take financial risk and the probability of taking out a loan for educational purposes as well as the influence of risk attitudes on the size of the loan using data drawn from the U.S. Survey of Consumer Finances. The findings suggest a positive relationship between individuals’ willingness to take financial risk and the probability of taking out a loan for educational purposes. Similarly, individuals’ willingness to take financial risk appears to be an important determinant of the size of the educational loan. The findings suggest that non-white individuals and individuals from less wealthy backgrounds are less likely to finance education through loans which could potentially increase inequalities in education and income if such individuals are deterred from investing in human capital