Handheld computers. A feasible alternative to paper forms for field data collection

Recent advances in handheld computer hardware and software may provide alternatives to paper-based data collection methods. The authors compared data collected with paper forms to data collected with handheld computer-based forms in a field observation study of alcohol purchase attempts at 47 community festivals in a large metropolitan area. Agreement between data collected with paper forms and data collected with handheld computers was greater than 95%. Computer-based forms handled branching patterns better and yielded data that were immediately available for analyses. Paper forms handled written comments better. Handheld computers are a feasible alternative to paper forms for field data collection.     

Effectiveness and Efficiency of Controlling Campylobacter on Broiler Chicken Meat

Campylobacter bacteria are an important cause of foodborne infections. We estimated the potential costs and benefits of a large number of possible interventions to decrease human exposure to Campylobacter by consumption of chicken meat, which accounts for 20-40% of all cases of human campylobacteriosis in the Netherlands. For this purpose, a farm-to-fork risk assessment model was combined with economic analysis and epidemiological data. Reduction of contamination at broiler farms could be efficient in theory. However, it is unclear which hygienic measures need to be taken and the costs can be very high. The experimental treatment of colonized broiler flocks with bacteriophages has proven to be effective and could also be cost efficient, if confirmed in practice. Since a major decrease of infections at the broiler farm is not expected in the short term, additional measures in the processing plant were also considered. At this moment, guaranteed Campylobacter-free chicken meat at the retail level is not realistic. The most promising interventions in the processing plant are limiting fecal leakage during processing and separation of contaminated and noncontaminated flocks (scheduling), followed by decontamination of the contaminated flock. New (faster and more sensitive) test methods to detect Campylobacter colonization in broilers flocks are a prerequisite for successful scheduling scenarios. Other methods to decrease the contamination of meat of colonized flocks such as freezing and heat treatment are more expensive and/or less effective than chemical decontamination.     

Modular Network Design: Using Information and Communication Technology to Allocate Production Tasks in a Virtual Organization*

The increased interest in customer service and the trend towards customization gives rise to new organizational forms such as the virtual organization. This paper introduces the Modular Network Design (MND) approach to complement Mowshowitz' (1997) theory of virtual organization. This theory focuses on metamanagement of the virtual organization and consists of four activities: (1) determine and analyze customer requirements, (2) track the possibilities for satisfying these requirements, (3) develop and allocate production tasks among the members of the virtual organization, and (4) assess and adjust tasks and allocation procedures. The MND approach elaborates on this theory by breaking down both the requirements and the production tasks into modular entities, and by measuring the performance of the resulting virtual network in terms of operating costs and throughput time. The major contribution of the MND approach lies in its ability to support the assessment of alternative allocations of production tasks among the members of a virtual organization, using Information and Communication Technology (ICT) as enabler. The assessment of such alternative designs is illustrated by an application of MND in the air cargo industry. The results show how the virtual organization and its members can realize significant improvements in operating costs and throughput times when applying ICT to link and reallocate their modular production tasks in response to customized orders.     

Strategic investment decisions in multi-stage contests with heterogeneous players

When heterogeneous players make strategic investment decisions in multi-stage contests, they might conserve resources in a current contest to spend more in a subsequent contest, if the degree of heterogeneity in the current (subsequent) contest is sufficiently large (small). We confirm these predictions using data from German professional soccer, in which players are subject to a one-match ban if they accumulate five yellow cards. Players with four yellow cards facing the risk of being suspended for the next match are (i) less likely to be fielded when the heterogeneity in the current match increases and (ii) more likely to receive a fifth yellow card in the current match when heterogeneity in the next match increases or heterogeneity in the next match but one (when they return from their ban) decreases.

     

The influence of need for closure on consumer’s choice behaviour

Consumers select a decision strategy in a purchase situation that best meets their goals for that situation. One of those possible goals is to obtain closure. The dimension need for closure (NFC) (vs. avoidance) reflects the desire for clear, definite, or unambiguous knowledge that will guide perception and action, as opposed to the undesirable alternative of ambiguity and confusion. The purpose of this study is to identify the influence of NFC on choice behaviour in a low involvement purchase situation. Both high (N=71) and low (N=71) NFC participants participated in a shopping experiment. In a simulated environment, participants were asked to choose repetitively between different brands within two low involvement product categories. We found significant differences between high and low NFC participants with regard to the amount of information sought, the amount of information used, the use of decision rules and the level of confidence in their decisions made. Marketing implications, limitations and directions for future research are also provided.     

Implementation of S-DBR in four manufacturing SMEs: a research case study

Production planning and control systems (PPCs) are tools that have a major effect on the performance of manufacturing companies. An inappropriate determination of the applicability of PPCs could seriously jeopardise the ability to achieve competitive priorities. This mistake can be expensive for any company, but proper implementation is particularly critical for small and medium enterprises (SMEs), which are characterised by limited access to financial resources. Simplified Drum–Buffer–Rope (S-DBR) is a PPC control approach that is characterised by minimum detail in the planning stage and a primary emphasis on the control of execution. Therefore, this approach is a suitable choice for the highly variable context of SMEs. This study aims to explore the practical issues related to S-DBR implementation in four Ecuadorian SMEs through case study research. The case analysis within this study first identifies the choices made in the implementation process design within the four companies according to process and product characteristics. We then conduct a cross-case analysis to explore the effects of the S-DBR implementation process designs on a group of performance measures. Our research findings provide new insights into the S-DBR implementation process in the context of SMEs, and the effects of this approach on performance measures.     

The forecasting performance of mortality models

Mortality projections are of special interest in many applications. For example, they are essential in life insurances to determine the annual contributions of their members as well as for population predictions. Due to their importance, there exists a huge variety of mortality forecasting models from which to seek the best approach. In the demographic literature, statements about the quality of the various models are mostly based on empirical ex-post examinations of mortality data for very few populations. On the basis of such a small number of observations, it is impossible to precisely estimate statistical forecasting measures. We use Monte Carlo (MC) methods here to generate time trajectories of mortality tables, which form a more comprehensive basis for estimating the root-mean-square error (RMSE) of different mortality forecasts.     

Central exit examinations increase performance... but take the fun out of mathematics

We study the causal effect of state-mandated (central) exit examinations (CEEs) on student performance in Germany and find a small positive effect. We also investigate what actually drives this effect. We find that the teachers’ main reaction to CEEs is to increase the amount of homework and to check and discuss homework more often. Students report increased learning pressure, which has sizeable negative effects on student attitudes toward learning. Students who take central exit exams in mathematics like mathematics less, think it is less easy, and are more likely to find it boring.     

Gender ideology, division of housework, and the geographic mobility of families

The paper studies the relevance of gender ideology for the geographic mobility of families using data from the German Socio-economic Panel. The analysis proceeds in two steps. First, it is shown that single men and women—who are in some sense “unconstrained” optimizers—reveal identical mobility patterns. There are no fundamental gender differences in the inter-regional mobility of German singles. Second, I focus on dual-earner households and split this group into “traditional” and “egalitarian” couples using information on their factual division of housework rather than their reported gender ideology. Separate migration analyses for both groups reveal important differences indicating the significance of gender ideology in families’ migration behavior: job-related characteristics of men statistically dominate those of women in traditional couples, whereas in egalitarian couples, male and female characteristics have the same effect on family migration behavior, i.e. there is no gender bias. Failure to account for the heterogeneity in gendered family roles across families thus misses an important explanatory factor in migration research.