A quantitative determination of the food security status of rural farming households in the Northern Province of South Africa

The majority of South Africans living in rural areas are food insecure despite high levels of national food self-sufficiency. The household food security position of two groups of rural farming households in the Venda region was evaluated quantitatively: one group produces vegetables that are sold or consumed locally, the other group produces cash crops – mangoes and other subtropical fruits. Using the collected data, food availability and energy, protein and fat requirements were calculated and balances derived. It was found that more than 80 per cent of the households had a negative balance of energy, protein and fat intake. The average energy, protein and fat coverage consumption was the same for both groups of farmers. A number of agricultural determinants were tested, but only non-agricultural determinants were found to be significant. These include household size, household (food) expenditure and proportion of the budget spent on food.     

Forces exerted by jumping children: a pilot study

Abstract

This article reports on a pilot study of the loads exerted vertically by children when jumping. The subjects of the study were 17 children, aged from two to twelve years. Measurements were made using video recordings and a force-plate. The influence of the stiffness of the base and of jumping with and without shoes was investigated. Knee flexion, push-off force (thrust) and the ratio between push-off force and body weight (relative thrust) were analyzed. Measurements of the knee flexion showed a certain consistency for each child. The angle of knee flexion during push-off follows a bimodal distribution with maxima at 60^° and 90^°. The results for relative thrust suggest a close relationship between push-off force and body weight.     

Container storage and transshipment marine terminals

This study addresses the storage arrangement of transshipment containers on a container yard, in order to carry out efficiently the ship handling operations at a terminal where mega-containerships call. An optimization model is specified to investigate the flow of containers from the mega-containership to feeder ships using intermediate storage at the yard. A heuristic based on the lagrangian relaxation is formulated. The quality of the heuristic approach is tested in a number of experiments. In the experiments, various situations are analyzed with respect to mega-containership arrival rates, some strategies for stack arrangements and terminal layouts.     

Statistical Analysis of Choice Experiments and Surveys

Measures of households' past behavior, their expectations with respect to future events and contingencies, and their intentions with respect to future behavior are frequently collected using household surveys. These questions are conceptually difficult. Answering them requires elaborate cognitive and social processes, and often respondents report only their “best” guesses and/or estimates, using more or less sophisticated heuristics. A large body of literature in psychology and survey research shows that as a result, responses to such questions may be severely biased. In this paper, (1) we describe some of the problems that are typically encountered, (2) provide some empirical illustrations of these biases, and (3) develop a framework for conceptualizing survey response behavior and for integrating structural models of response behavior into the statistical analysis of the underlying economic behavior.     

An Investigation of the Association between Cultural Dimensions and Variations in Perceived Use of and Compliance with Internal Auditing Standards in 19 Countries

Using a large sample of chief audit executives and internal audit managers from 19 countries, we investigate potential associations between cultural dimensions and variations in perceived use/compliance with the internal auditing standards. We find uncertainty avoidance to be inversely related to both use and compliance. We also find assertiveness and human orientation to be positively related to compliance but not to use of Standards. Among control variables, we find positive associations for the length of Institute of Internal Auditors (IIA) membership, professional certification in internal auditing, and hours of continuing professional education (CPE) training on both perceived use and compliance. Finally, we find “Cost of compliance” and “Compliance not expected in my country” to be inversely related to perceived use/compliance. Implications of these findings are discussed.     

The co‐evolution of capabilities and transaction costs: explaining the institutional structure of production

This paper proposes that transaction costs and capabilities are fundamentally intertwined in the determination of vertical scope, and identifies the key mechanisms of their co‐evolution. Specifically, we argue that capability differences are a necessary condition for vertical specialization; and that transaction cost reductions only lead to specialization when capabilities along the value chain are heterogeneous. Furthermore, we argue that there are four evolutionary mechanisms that shape vertical scope over time. First, the selection process, itself driven by capability differences, dynamically shapes vertical scope; second, transaction costs are endogenously changed by firms that try to reshape the transactional environment to increase their profit and market share; third, changes in vertical scope affect the nature of the capability development process, i.e., the way in which firms improve their operations over time; and finally, the changes in the capability development process reshape the capability pool in the industry, changing the roster of qualified participants. These dynamics of capability and transaction cost co‐evolution are illustrated through two contrasting examples: the mortgage banking industry in the United States, which shows the shift from integrated to disintegrated production; and the Swiss watch‐manufacturing industry, which went from disintegration to integration. Copyright © 2005 John Wiley & Sons, Ltd.     

Pure vs. mixed commodity bundling

In the commodity bundling literature, pure bundling is ruled out as a uniquely optimal strategy because mixed bundling is always (weakly) better. This paper provides a theoretical distinction between the two pricing schemes. The distinction relies on the degree of consumer heterogeneity in reservation prices. While there is a lack of empirical evidence on commodity bundling pricing schemes due to the difficulties in measuring consumer heterogeneity, we circumvent this problem by examining firm heterogeneity. Specifically, we use data from the newspaper industry in which some two edition newspaper firms are mixed bundlers and others are pure bundlers.     

An alternate development of conditioning

Abstract  The "classical" development of conditioning, due to K olmogorov , does not agree with the "practical" (more intuitive, but unrigorous) way in which probabilists and statisticians actually think about conditioning. This paper describes an alternative to the classical development. It is shown that standard concepts and results can be developed, rigorously, along lines, which correspond to the "practical" approach, and so as to include the classical material as a special case. More specifically, let Xand Y be random variables (r.v.'s) from (Ω, f, P) to ( x, f_x ) and (y. f^y.), respectively. In this paper, the fundamental concept is the conditional probability P(AX = x ), a function of xε x which satisfies a "natural" defining condition. This is used to define a conditional distribution P_y/x, as a mapping x × f^y-R such that, as a function of B, P_ylx=x,(B ) is a probability measure on f^y. Then, for a numerical r.v. Y , conditional expectation E(Y/X) is defined as a mapping x → whose value at x isE(Y/X = x) = ydP_Y/x=i(y ). Basic properties of conditional probabilities, distributions, and expectations, are derived and their existence and uniqueness are discussed. Finally, for a sub-o-algebra and a numerical r.v. Y , the classical conditional expectation E(Y) is obtained as E(Y/X) with X = i , the identity mapping from (Ω, f) to (Ω).