The reliability of constructs derived from attitude-behavior theories: an application of generalizability theory in the health sector

Theories of reasoned action, interpersonal behavior and self-efficacy have been frequently used for research into health-related behavior. The present study investigated two methods for assessing the reliability of their theories' constructs: the test-retest method and generalizability theory. Firstly, it is demonstrated with a numerical example that the traditional test-retest coefficient has an anatomical link with the generalizability coefficient. Secondly, generalizability theory was applied in order to identify the number of occasions each construct must be measured to assure its reliability. This procedure was applied to the data collected in a study investigating the psychosocial factors influencing exercising and smoking behaviors among pregnant women. Measuring the constructs of direct attitude, habit, and intention on only one occasion was sufficient to ensure high levels of reliability. Moreover, reliability of the other constructs would be ensured if they were measured on more than one occasion.     

New technology based firms and the creation of regional growth potential

This paper focuses on the role of New Technology Based Firms (NTBFs) as a vital determinant of regional growth potential. The theoretical framework starts from the relation between innovation and economic development (macro-approach), to show how NTBFs can contribute to the creation of a regional growth potential (micro-approach). Empirical data for Belgium illustrate how NTBFs differ significantly from common starters on a number of fundamental characteristics such as educational level, product/market-orientation, socio-economic networking, delegation, growth strategy and Research and Development. Taking these findings into account, we concentrate on the region-specific technology policies in Belgium. The case of the emerging biotechnology industry is used as an illustration.     

The right to food in historical perspective

The right to food is the most fundamental of economic rights. The author disagrees with pessimists who claim that economic rights will never be ensured due to opposition from those who take advantage of the status quo, and believes that social transformations can occur, as history has shown. After outlining the historical background to the right to food, he identifies processes of deprivation in the 1980s, such as the impact of pricing policies, and food insecurity among the urban poor. Finally he outlines some recommendations to Third World governments seeking to ensure the right of food to its peoples.     

在低维空间实现的基于MP的图像稀疏分解

研究利用Matching Pursuit(MP)方法实现的图像稀疏分解算法，针对其中关键难题，提出利用在低维空间的搜索实现高维空间的搜索的快速方法。算法的有效性为实验结果所证实。     

The Macroeconomic Consequences of Reciprocity in Labor Relations*

We develop and analyze a structural model of efficiency wages founded on reciprocity. Workers are assumed to face an explicit trade‐off between the disutility of providing effort and the psychological benefit of reciprocating the gift of a wage offer above some reference level. The model provides a rationale for rent sharing—a feature that is very much present in the data but absent from previous formulations of the efficiency wage hypothesis. This firm‐internal perspective on efficiency wages has potentially important macroeconomic consequences: rent‐sharing considerations promote wage rigidity, internal amplification and differential responses to technology and demand shocks.     

The information content of implied volatility in agricultural commodity markets

In this article we compare the incremental information content of lagged implied volatility to GARCH models of conditional volatility for a collection of agricultural commodities traded on the New York Board of Trade. We also assess the relevance of the additional information provided by the implied volatility in a risk management framework. It is first shown that past squared returns only marginally improve the information content provided by the lagged implied volatility. Secondly, value‐at‐risk (VaR) models that rely exclusively on lagged implied volatility perform as well as VaR models where the conditional variance is modelled according to GARCH type processes. These results indicate that the implied volatility for options on futures contracts in agricultural commodity markets provides relevant volatility information that can be used as an input to VaR models. © 2003 Wiley Periodicals, Inc. Jrl Fut Mark 23:441–454, 2003