Predictive safety analytics: inferring aviation accident shaping factors and causation

This paper illustrates the development of an object-oriented Bayesian network (OOBN) to integrate the safety risks contributing to an in-flight loss-of-control aviation accident. With the creation of a probabilistic model, inferences about changes to the states of the accident shaping or causal factors can be drawn quantitatively. These predictive safety inferences derive from qualitative reasoning to conclusions based on data, assumptions, and/or premises, and enable an analyst to identify the most prominent causal factors leading to a risk factor prioritization. Such an approach facilitates a mitigation portfolio study and assessment. The model also facilitates the computation of sensitivity values based on perturbations to the estimates in the conditional probability tables. Such computations lead to identifying the most sensitive causal factors with respect to an accident probability. This approach may lead to vulnerability discovery of emerging causal factors for which mitigations do not yet exist that then informs possible future R&D efforts. To illustrate the benefits of an OOBN in a large and complex aviation accident model, the in-flight loss-of-control accident framework model is presented.     

Non-parametric and parametric bootstrap techniques for age-to-age development factor methods in stochastic claims reserving

In the literature, one of the main objects of stochastic claims reserving is to find models underlying the chain-ladder method in order to analyze the variability of the outstanding claims, either analytically or by bootstrapping. In bootstrapping these models are used to find a full predictive distribution of the claims reserve, even though there is a long tradition of actuaries calculating the reserve estimate according to more complex algorithms than the chain-ladder, without explicit reference to an underlying model. In this paper we investigate existing bootstrap techniques and suggest two alternative bootstrap procedures, one non-parametric and one parametric, by which the predictive distribution of the claims reserve can be found for other age-to-age development factor methods than the chain-ladder, using some rather mild model assumptions. For illustration, the procedures are applied to three different development triangles.     

Cost structure and capacity in the Norwegian pelagic fisheries

The parameters of the short-run cost function are estimated for three vessel types taking part in the Norwegian pelagic fisheries: purse seine vessels, trawlers, and coastal vessels. The generalized translog functional form is used. Estimates of returns to scale are calculated and the results indicate that there are substantial economies of scale in all vessel classes. It is further investigated whether excess capacity varies with vessel size and age. The analysis suggests increased quotas per vessel to avoid rent dissipation. With the total allowable catch given, the number of participating vessels must be reduced.     

What money buys: clients of street sex workers in the US

The article presents a review of current theoretical and empirical approaches to sex work, followed by the presentation of an original theoretical framework (Della Giusta et al., 2006), which is tested with an econometric model of the characteristics of demand for sex services by a sample of clients of street sex workers in the US. We present findings in relation to stigma and the relationship between paid and unpaid sex that corroborate our model's hypotheses and are in line with findings from other empirical studies. Furthermore, we identify in our sample two diametrically opposite profiles: one for clients whom we label ‘experimenters’, and one for more experienced ones that we name ‘regulars’, we also estimate attitudes toward risk, and draw implications in terms of both policy and future theoretical and empirical research.     

A stable demand for money despite financial crisis: the case of Venezuela

The demand for broad money in Venezuela is investigated over a period of financial crisis and substantial exchange rate fluctuations. The analysis shows that there exist a long-run relationship between real money, real income, inflation, the exchange rate and an interest rate differential, that remains stable over major policy changes and large shocks. The long-run properties emphasize that both inflation and exchange rate depreciations have negative effects on real money demand, whereas a higher interest rate differential has positive effects. The long-run relationship is finally embedded in a dynamic equilibrium correction model with constant parameters. These results have implications for a policy-maker. In particular, they emphasize that with a high degree of currency substitution in Venezuela, monetary aggregates will be very sensitive to changes in the economic environment.     

The impact from changes in stock market valuations on investment: new economy versus old economy

This paper investigates whether there is a different impact from changes in ‘new’ and ‘old’ economy stock valuations on private investment for seven OECD economies. A vector autoregressive model is estimated for each individual country, using quarterly data over the period 1990–2000. It is found that the impact from changes in valuations of new economy stocks to investment is roughly the same in North America and in the United Kingdom as in continental Europe. By contrast, the impact from changes in old economy stock valuations on investment is, in general, larger in North America and in the United Kingdom than in continental Europe. Finally, the results suggest that in continental Europe the impact on investment from changes in the valuation of new economy stocks is bigger than for old economy stocks, whereas for North America and the United Kingdom, the impact is more similar.     

Can student effort be manipulated? Does it matter?

This article provides evidence that college students’ effort can be manipulated substantially by making changes in the college testing regime and moreover that student effort is a meaningful input in education production. The evidence comes from a quasi-experiment where a mid-semester test with a pass requirement is introduced to a mandatory one-semester Business School course in Macroeconomics. Four cohorts of students – one before and three after the introduction of the pass requirement – have reported their study effort twice during the semester, and the relationship between achievement and study effort is investigated by using a within-subject within-student across-study periods approach.     

Role of gastronomic,externality and feasibility attributes in consumer demand for organic and local foods: The case of honey and apples

Local food systems providing high‐value products are seen as a tool to sustain economic activity on family farms in rural areas. The objective of this study is to investigate the role of gastronomic, externality and feasibility characteristics in consumers' demand for local and for organic foods. An Internet questionnaire survey was conducted in 2010 among Danish consumers. 3211 respondents completed the questionnaire, which included questions about respondents' food‐related values and their specific perception of organic and local varieties of honey and apples. Variables related to consumers' food‐related values and product perception were analysed using principal component analysis, in order to identify overall dimensions (factors) in these variables. Although statements about gastronomic attributes (e.g. taste, appearance, quality) were quite strongly represented in three of these factors, externality and availability concerns also contributed significantly to the overall variation in the variables. Multinomial logit choice modelling was used for describing the relationship between these dimensions and respondents' stated choices regarding organic and local varieties of honey and apples. Results suggest that although both organic and local food supply chains are often associated with special attributes such as gastronomic characteristics and relatively beneficial externality attributes, these attributes are perceived differently for the two types of supply chains. Perceived gastronomic quality is the most important determinant for food choice, but externality and feasibility aspects are also important correlates.     

Consumer understanding of food labels: toward a generic tool for identifying the average consumer

The ‘average consumer’ is referred to as a standard in regulatory contexts when attempts are made to benchmark how consumers are expected to reason while decoding food labels. An attempt is made to operationalize this hypothetical ‘average consumer’ by proposing a tool for measuring the level of informedness of an individual consumer against the national median at any time. Informedness, i.e. the individual consumer's ability to interpret correctly the meaning of the words and signs on a food label is isolated as one essential dimension for dividing consumers into three groups: less-informed, informed, and highly informed consumers. Consumer informedness is assessed using a 60-question test related to information found on a variety of Danish everyday food products and divided into factual questions and informedness about signpost labels. A test was made with 407 respondents who participated in four independent studies on fairness in consumer communication, and the average score for all was 57.6% of correct answers. A score of 64% and beyond would place a consumer in the upper quartile (the group of highly informed consumers), whereas a score of 52% or below would place the individual in the lower quartile (the group of less-informed consumers). Female respondents performed better than males on label recognition, and those around 40 years of age irrespective of gender performed best on factual knowledge, whereas those aged around 30 performed best on label recognition. It is foreseen that independent future studies of consumer behavior and decision making in relation to food products in different contexts could benefit from this type of benchmarking tool.