Empirical testing of alternative price spread models in the South African maize market

Reduced-form price spread models have been recently utilized by Wohlgenant and Mullen, and Thompson and Lyon to evaluate the economic factors affecting the marketing margins for agricultural products. Drawing on Gardner, Heien, Buse and Brandow, Waugh, Tomek and Robinson, and others they specify alternative retail-farm price spread models and attempt to determine which best fit the data in the context of underlying theoretical rationale. This paper continues in the spirit of Wohlgenant and Mullen, and Thompson and Lyon by evaluating alternative specifications of the retail-farm price spread for white maize in South Africa. However, several important differences do remain. Wohlgenant and Mullen analyzed the price spread for beef using annual data, while Thompson and Lyon modeled the price spread for oranges using weekly data. The time period under consideration can be expected to affect the choice of model because fixed markup rules that might be evident using a short-run period of analysis (e.g., Thompson and Lyon) become untenable over the long run with underlying supply and demand shifts. In this paper, monthly data, which may be interpreted as an intermediate-run period, are used along with dichotomous supply-demand shifters. In addition, Brorsen et. al. have shown that price uncertainty affects the price spread in the marketing channels of agricultural commodities. Thus, the analysis in this paper extends the framework of Wohlgenant and Mullen, and Thompson and Lyon to include measures of price risk. Finally, like Brorsen et. al. this study pertains to the grain market, while Wohlgenant and Mullen, and Thompson and Lyon studied the marketing margin for non-storable commodities.     

The accuracy of OECD forecasts

This paper examines the accuracy and properties of forecasts by the OECD for 24 countries and 8 variables. First the forecasts made in December of yeart?1 for yeart are examined, with the largest errors being for investment, industrial production and foreign balance. Next the way forecasts are revised between December and July is considered. Systematic revisions occur for Iceland, Turkey and Luxembourg. Finally the accuracy of forecasts made before, during and after the 1979 oil price rises are compared, and no evidence of a worsening of accuracy is found.     

Cross-national differences in trade union membership in OECD countries

This article examines how trade union membership varies across 16 OECD countries in the 1980s. Higher density of membership is found to be associated with a higher degree of centralisation of wage bargaining, higher percentage of employees covered by collective bargaining, a larger public sector and a more leftist party of government.     

Monetary regimes and the co-ordination of wage setting

A recent literature argues that a strict monetary regime may reduce equilibrium unemployment by disciplining wage setters, as wage setters abstain from raising wages to avoid a monetary contraction. However, in this literature the wage setters are assumed not to co-ordinate their wage setting. The present paper argues that precisely because a strict monetary regime may discipline the unco-ordinated wage setting, thus lowering unemployment in the unco-ordinated outcome, it also reduces wage setters’ incentives to co-ordinate. It is shown that an accommodating monetary regime may reduce equilibrium unemployment, via the strengthening of the wage setters’ incentives to co-ordinate.     

Institutional strategies for dealing with sexual harassment

Sexual harassment is being recognized as a pervasive and highly visible problem at an institutional level. As a consequence institutions are establishing policies and procedures to address this issue. In view of recent legal decisions, sexual harassment can have negative consequences for the institution as well as the harassee; thus, in some institutions, sexual harassment is viewed as a common problem shared by employers and employees. This article addresses institutional strategies that have proven effective in proactively dealing with sexual harassment in the workplace.     

Risk aversion, liquidity, and endogenous short horizons

We analyze a competitive model in which different informationsignals get reflected in value at different points in time.If investors are sufficiently risk averse, we obtain an equilibriumin which all investors focus exclusively on the short term.In addition, we show that increasing the variance of informationlesstrading increases market depth but causes a greater proportionof investors to focus on the short-term signal, which decreasesthe informativeness of prices about the long run. Finally, wealso explore parameter spaces under which long-term informedagents wish to voluntarily disclose their information.