Exact arbitrage, well-diversified portfolios and asset pricing in large markets

For a market with an atomless continuum of assets, we formulate the intuitive idea of a “well-diversified” portfolio, and present a notion of “exact arbitrage”, strictly weaker than the more conventional notion of “asymptotic arbitrage”, and necessary and sufficient for the validity of an APT pricing formula. Our formula involves “essential” risk, one based on a specific index portfolio constructed from factors and factor loadings that are endogenously extracted to satisfy an optimality property involving a finite number of factors. We illustrate how our results can be translated to markets with a large but finite number of assets.     

Integrating public service and marketing differentiation: an analysis of the American Express Corporation’s “Charge Against Hunger” promotion program

Dating back to the 1980s, American Express (AMEX) has been a corporate leader in successfully applying cause-related marketing (CRM) to boost membership and credit card usage in troubled markets. During a downturn in the mid-1990s, AMEX and Share Our Strength (SOS), a nonprofit organization tackling the problem of hunger in the United States, formed a strategic alliance to create one of the best known and most highly touted CRM campaigns. AMEX implemented an innovative cause branding (CB) effort to convince its cardholders to “Charge Against Hunger” (CAH) by utilizing their AMEX credit cards more frequently during the holiday season. Over the 4-year life of the program, the issue of hunger in the United States was put somewhat higher on the public agenda as more than US $21 million were raised for SOS projects. This study assesses how AMEX’s public relations efforts contributed to the success of the CAH campaign.     

On Testing the Random-Walk Hypothesis: A Model-Comparison Approach

The main intention of this paper is to investigate, with new daily data, whether prices in the two Chinese stock exchanges (Shanghai and Shenzhen) follow a random‐walk process as required by market efficiency. We use two different approaches, the standard variance‐ratio test of Lo and MacKinlay (1988) and a model‐comparison test that compares the ex post forecasts from a NAÏVE model with those obtained from several alternative models: ARIMA, GARCH and the Artificial Neural Network (ANN). To evaluate ex post forecasts, we utilize several procedures including RMSE, MAE, Theil's U, and encompassing tests. In contrast to the variance‐ratio test, results from the model‐comparison approach are quite decisive in rejecting the random‐walk hypothesis in both Chinese stock markets. Moreover, our results provide strong support for the ANN as a potentially useful device for predicting stock prices in emerging markets.     

Customer perception and competitive quality strategy

The objective of this paper is to determine the optimum level of quality a firm should choose in a product/service, given the customers‘ perceptions of quality and the reference standard in a competitive market. Our work on this quality selection problem differs from those of past researchers in that we model explicitly customer's perceptions and the reference standard. We develop a game-theoretic model to obtain insights into the firms’ quality selection problem. The model results suggest that the market differentially provides rewards or penalties to firms depending upon customers' perceptions as well as other market and product-specific parameters. We contrast our findings for an oligopolist with that for a monopolist and observe that although an oligopolist often provides a better quality product, he does not do so always; especially when perceptions are sufficiently weak and the reference standard is endogenous.     

The Significance of Working Time Arrangements Accompanying the Introduction of Teamworking: Evidence from Employees

A study is reported where the introduction of teamworking was accompanied by negotiated changes in working time patterns, involving some employees transferring to a 5‐shift, 8‐hour pattern, others to a 5‐shift, 12‐hour pattern. Employee attitude surveys before and after the changes show those moving to 12‐hour working much more satisfied with both working time and other changes, compared with those remaining on 8‐hour shifts. The creation of extra non‐work days was seen as the major advantage of the longer shifts, which compensated for the harder work regime identified under teamworking and the greater rigidity of the 5‐shift system. The findings underline the potential significance of working hours for employee support for broader changes in working practices. Possible explanations of why the longer shift pattern met with considerable support at one research site, but failed to gain support at a similar site elsewhere, are also explored.     

Editorial introduction: Is the World Bank lending effective in developing countries?

This special issue of Economic Systems includes five papers about the World Bank lending in developing countries. The motivation for the special issue stems from the relatively extensive literature on the sister institution, namely, the International Monetary Fund (IMF), but not on the World Bank itself. The papers’ focus is the influence of the World Bank lending on economic growth, education and health, poverty reduction, and regulation in the recipient countries. The papers’ findings contribute to our understanding of the effects of the World Bank lending in developing countries, which reflects both successes and shortcomings.     

Self-Interest, Self-Deception and the Ethics of Commerce

On taking the common distinction between the legal and the ethical as a point of departure, and in an effort to understand Marshall's approach to self-interest, and thereby to his conception of an ethics of commerce, I read three of his essays in the light of some non-technical writings of Frank Hahn and three other Cambridge intellectuals. My larger project connects self-interest and self-deception to a possible ethics of theorizing in economics, and thereby to the ethics of the relationship between the theorist and the theorized, the analyst and the analyzed.     

Determinants of fertility in developing countries

The contribution of agricultural modernization to changes in fertility in developing countries was examined. A model for the determinants of both fertility and infant mortality--hypothesized to be positively related--was specified and applied to cross-sectional data for 75 developing countries for the year 1971. The infant mortality rate, productivity per unit of labor and land, and density of population for agricultural land were highly correlated with the crude birth rate. The only other exogenous variables highly correlated with each other were productivity per unit of labor and infant mortality, and productivity per unit of land and population density for agricultural areas. The coefficient of population density of agricultural areas suggested a negative impact of density on fertility. The infant mortality rate, productivity per unit of land and labor, and density of population of agricultural areas explained 85% of the intercountry variation in fertility. The infant mortality rate, productivity of land, and productivity of labor were of descending order of importance in determining the crude birth rates in the countries analyzed. 68% of the intercountry variation in infant mortality was explained by fertility, adult literacy, per capita energy consumption, gini-coefficient of income distribution, population per hospital bed, and protein supply. Adult literacy, crude birth rates, population per hospital bed, per capita energy consumption, per capita protein supply, and gini-coefficient of income distribution were of descending order of importance in determining infant mortality rates. All of the variables that affected infant mortality directly affected fertility indirectly; conversely, all the variables that affected fertility directly affected infant mortality indirectly. Overall, these results confirm that agricultural modernization does exert an effect on fertility. The task in developing countries is to break the vicious cycle of infant mortality and fertility. This can be achieved both through family planning programs and the diffusion of health programs to lower infant mortality.     

Navigating towards sustainable development: A system dynamics approach

Traditional fragmented and mechanistic science is unable to cope with issues about sustainability, as these are often related to complex, self-organizing systems. In the paper, sustainable development is seen as an unending process defined neither by fixed goals nor by specific means of achieving them. It is argued that, in order to understand the sources of and the solutions to modern problems, linear and mechanistic thinking must give way to non-linear and organic thinking, more commonly referred to as systems thinking. System Dynamics, which operates in a whole-system fashion, is put forward as a powerful methodology to deal with issues of sustainability. Examples of successful applications are given.Any system in which humans are involved is characterized by the following essential system properties: Bounded rationality, limited certainty, limited predictability, indeterminate causality, and evolutionary change. We need to resort to an adaptive approach, where we go through a learning process and modify our decision rules and our mental models of the real world as we go along. This will enable us to improve system performance by setting dynamic improvement goals (moving targets) for it.Finally, it is demonstrated how causal loop diagrams can be used to find the leverage points of a system.