Interpersonal Distances in Group Walking

The spatial organization of 1,020 groups comprised of adolescents and young adults, observed in an ecological setting while walking, was analyzed. Observations were made in an urban environment where walking speed could be considered. The results showed that male dyads and triads tended to walk abreast less often than female dyads. Mixed dyads walked abreast more often than same-sex dyads; and the males preceded the females in two-thirds of the cases. The male groups walked at a higher rate of speed than the female groups. Walking speed was correlated to misalignment between group members when walking. The most frequent spatial arrangement in triads was a “<” formation (as seen from above, while the walking direction was from left to right), with the middle individual positioned slightly behind in comparison to the lateral individuals. Groups comprised of more than three individuals tended to split themselves into single individuals, dyads, and triads.     

The Granular Origins of Aggregate Fluctuations

This paper proposes that idiosyncratic firm‐level shocks can explain an important part of aggregate movements and provide a microfoundation for aggregate shocks. Existing research has focused on using aggregate shocks to explain business cycles, arguing that individual firm shocks average out in the aggregate. I show that this argument breaks down if the distribution of firm sizes is fat‐tailed, as documented empirically. The idiosyncratic movements of the largest 100 firms in the United States appear to explain about one‐third of variations in output growth. This “granular” hypothesis suggests new directions for macroeconomic research, in particular that macroeconomic questions can be clarified by looking at the behavior of large firms. This paper's ideas and analytical results may also be useful for thinking about the fluctuations of other economic aggregates, such as exports or the trade balance.     

Strategic Supply Function Competition With Private Information

A finite number of sellers (n) compete in schedules to supply an elastic demand. The cost of each seller is random, with common and private value components, and the seller receives a private signal about it. A Bayesian supply function equilibrium is characterized: The equilibrium is privately revealing and the incentives to rely on private signals are preserved. Supply functions are steeper with higher correlation among the cost parameters. For high (positive) correlation, supply functions are downward sloping, price is above the Cournot level, and as we approach the common value case, price tends to the collusive level. As correlation becomes maximally negative, we approach the competitive outcome. With positive correlation, private information coupled with strategic behavior induces additional distortionary market power above full information levels. Efficiency can be restored with appropriate subsidy schemes or with a precise enough public signal about the common value component. As the market grows large with the number of sellers, the equilibrium becomes price‐taking, bid shading is on the order of 1/n, and the order of magnitude of welfare losses is 1/n². The results extend to inelastic demand, demand uncertainty, and demand schedule competition. A range of applications in product and financial markets is presented.     

The Sichel model and the mixing and truncation order

The analysis of word frequency count data can be very useful in authorship attribution problems. Zero-truncated generalized inverse Gaussian–Poisson mixture models are very helpful in the analysis of these kinds of data because their model-mixing density estimates can be used as estimates of the density of the word frequencies of the vocabulary. It is found that this model provides excellent fits for the word frequency counts of very long texts, where the truncated inverse Gaussian–Poisson special case fails because it does not allow for the large degree of over-dispersion in the data. The role played by the three parameters of this truncated GIG-Poisson model is also explored. Our second goal is to compare the fit of the truncated GIG-Poisson mixture model with the fit of the model that results from switching the order of the mixing and truncation stages. A heuristic interpretation of the mixing distribution estimates obtained under this alternative GIG-truncated Poisson mixture model is also provided.     

Selecting significant effects in factorial designs: Lenth's method versus using negligible interactions

Among the many analytical techniques that have been published to analyze the significance of the effects in the absence of replications, two have emerged as the most widely used in text books as well as statistical software packages: The Lenth's method and the estimation of the variance of the effects from the values of those considered negligible. This article shows that neither is better than the other in all cases, and by analyzing the results obtained in a wide variety of situations it provides guidelines on when it is preferable to use one or the other technique.     

Women Acting for Women

In the new country of Timor-Leste, women constituted in 2011 32 per cent of the parliament, a relatively high figure in the world and in the region. But to what extent has the presence of women in parliament contributed to progress towards gender equality? In this article we argue that the passage of a parliamentary resolution on gender-responsive budgeting in Timor-Leste was an act of substantive representation, and we draw on a range of data to examine what made it possible. We find that while ‘newness’, international norms, women's movement unity, women's machinery in government and parliament and networks linking them were important, it was the development of a cross-party parliamentary women's caucus that was crucial to success. The role of gender-focused parliamentary institutions in supporting critical actors has rarely been examined in the literature on substantive representation. This is in contrast to the rich literature on institutions such as women's policy agencies. Our study suggests that more focus on parliamentary institutions is needed to discover what enables women parliamentarians to become critical actors.     

A multicriteria decision analysis model for faculty evaluation

In the context of increasing demands for social and financial accountability of universities, the required implementation of transparent faculty evaluation systems constitutes a challenge and an opportunity for universities strategically aligning the activity of academic staff with the university goals. However, despite growing interest in the performance appraisal of faculty, only a few reported studies propose models that cover the full range of academic activities and the models in use are typically based on ad hoc scoring systems that lack theoretical soundness. This article approaches faculty evaluation from an innovative comprehensive perspective. Based on the concepts and methods of multiple criteria value measurement, it proposes a new faculty evaluation model that addresses the whole range of academic activities and can be applied within and across distinct scientific areas, while respecting their specificities. Constructed through a socio-technical process, the model was designed for and adopted by the Instituto Superior Técnico, the engineering school of the Technical University of Lisbon. The model has a two-level hierarchical additive structure, with top-level evaluation areas specified by second-level evaluation criteria. A bottom non-additive third level accounts for the quantitative and qualitative dimensions of academic activity related to each evaluation criterion. The model allows (a) the comparison of the performance of academic staff with performance targets reflecting the strategic policy concerns of university management; (b) the definition of the multicriteria value profile of each faculty member at the top level of the evaluation areas; (c) the computation of an overall value score for each faculty member, through an optimisation procedure that makes use of a flexible system of weights and (d) the assignment of faculty members to rating categories.     

Understanding the twentieth-century decline in chronic conditions among older men

I argue that the shift from manual to white-collar jobs and reduced exposure to infectious disease were important determinants of declines in chronic disease rates among older men from the early 1900s to the 1970s and 1980s. The average decline in chronic respiratory problems, valvular heart disease, arteriosclerosis, and joint and back problems was about 66%. Occupational shifts accounted for 29% of the decline; the decreased prevalence of infectious disease accounted for 18%; the remainder are unexplained. The duration of chronic conditions has remained unchanged since the early 1900s, but when disability is measured by difficulty in walking, men with chronic conditions are less disabled now than they were in the past.     

Mapping social and environmental concerns and the acceptability of genetically modified organisms in the European Union

Simultaneous conflicting attitudes towards an object make both predicting and explaining behaviour a complex endeavour. This paper explores the hypothesis of social ambivalence (so called as well or approach-avoidance conflict) as a phenomenon influencing attitudes towards the environmental effects of the introduction of GMOs (Genetic Modified Organisms). If social ambivalence exists it would be suggestive of an interplay between rational models or behaviour and normative or moral models of behaviour. This paper provides some quantitative analysis based on a representative sample of the European Union, using unique data from the Eurobarometer 58.0 (2002) examining public perceptions of environmental risks. Our findings suggest that GMOs are perceived as having a non-neutral impact on the environmental and social life and that as hypothesized there is evidence of social ambivalence, which appears to be more significant when environmental effects of GM foods are taken into account. Consistently with the hypothesis of interplay between rational and normative models of behaviour, respondents perceive some risks while benefits are not perceived by the public and moral concerns regarding technologies being developed by international corporations are important. A specific type of social ambivalence is found, namely GMO are not accepted for Europeans but they are in less developed countries.