A robust test for asymptotic independence of bivariate extremes

We show that the existing tests for asymptotic independence are sensitive to outliers. A robust test is proposed. The new test is made stable under contamination through a shrinkage scheme. Simulations show that the new test performs well in the presence of contaminated data while maintaining good properties when there is no contamination. An application to real data shows the added value of our new robust approach.     

A Demographic Model of Measles Epidemics

Liverpool, U.K., 1863--1900, has been used as a model to explore the interaction between measles epidemics and the population dynamics in an overcrowded community with inadequate nutrition using a non-linear model which allows the estimation of certain underlying demographic parameters. The results are consistent with a system that is driven by an oscillation in the transmission parameter that is compounded of an oscillation in autumn temperatures (at the resonant frequency of the system, 2.4 years) and, secondarily, by an oscillation in wheat prices (wavelength = 5.3 years, twice that of the epidemics).     

Behavioral responses and the distributional effects of the Russian ‘flat’ tax

This paper simulates the distributional impact of the Russian personal income tax (PIT) following the flat tax reform of 2001 using data from the Russian Longitudinal Monitoring Survey. I decompose the change in the distribution of net income into a direct (tax) effect and an indirect effect. The indirect effect is further decomposed into evasion and productivity effects using existing estimates of these respective elasticities. As expected, the direct tax effect increased net income inequality. Changes in the pre-tax distribution (indirect effect), on the other hand, had a large negative impact on inequality thus leading to an overall decline in net income inequality. I also find that the tax-induced evasion response increased reported net income inequality while reducing consumption inequality. To the extent that consumption approximates actual income, these results demonstrate that the flat tax reform had a much smaller effect on actual income inequality than on reported income inequality. More importantly, relative to non-tax factor, the reform had little overall effect on income inequality. This suggests that objection to flatter tax schedules on the grounds of income inequality is mostly misguided, especially in transitional countries with high levels of evasion.     

Interpersonal comparisons of utility for 2 of 3 types of people

This article argues that there is a natural solution to carry out interpersonal comparisons of utility when the theory of gambles is supplemented with a group operation of joint receipts. If so, three types of people can exist, and the two types having multiplicative representations of joint receipt have, in contrast to most utility theories, absolute scales of utility. This makes possible, at least in principle, meaningful interpersonal comparisons of utility with desirable properties, thus resolving a long standing philosophical problem and having potentially important implications in economics. Two behavioral criteria are given for the three classes of people. At this point the relative class sizes are unknown.     

Fast computation of spatially adaptive kernel estimates

Kernel smoothing of spatial point data can often be improved using an adaptive, spatially varying bandwidth instead of a fixed bandwidth. However, computation with a varying bandwidth is much more demanding, especially when edge correction and bandwidth selection are involved. This paper proposes several new computational methods for adaptive kernel estimation from spatial point pattern data. A key idea is that a variable-bandwidth kernel estimator for d-dimensional spatial data can be represented as a slice of a fixed-bandwidth kernel estimator in \((d+1)\)-dimensional scale space, enabling fast computation using Fourier transforms. Edge correction factors have a similar representation. Different values of global bandwidth correspond to different slices of the scale space, so that bandwidth selection is greatly accelerated. Potential applications include estimation of multivariate probability density and spatial or spatiotemporal point process intensity, relative risk, and regression functions. The new methods perform well in simulations and in two real applications concerning the spatial epidemiology of primary biliary cirrhosis and the alarm calls of capuchin monkeys.     

Positive Changes in Perceptions and Selections of Healthful Foods by College Students After a Short-Term Point-of-Selection Intervention at a Dining Hall

Abstract

Objective: Determine the effects of a short-term, multi-faceted, point-of-selection intervention on college students’ perceptions and selection of 10 targeted healthful foods in a university dining hall and changes in their self-reported overall eating behaviors. Participants: 104 college students, (age 18–23) completed pre-I and post-I surveys. Methods: Pre-survey collected at dining hall in April 2007, followed by 3-week intervention then post-survey collected via email. Healthy choice indicators, large signs, table tents, flyers and colorful photographs with “benefit-based messages” promoted targeted foods. Response rate to both surveys was 38%. Results: Significantly more participants reported that healthful choices were clearly identified in the dining hall after the intervention. Over 20% of participants reported becoming more aware of healthful food choices in the dining hall after the intervention. Significant increases in self-reported intake were reported for cottage cheese and low-fat salad dressing, with a trend toward increased consumption of fresh fruit. Seven of the 14 assessed eating behaviors had significant changes in the desired direction. Increased awareness of healthful foods was the top reason for self-reported changes in overall eating behaviors. Conclusion: Short-term, multi-faceted, point-of-selection marketing of healthful foods in university dining halls may be beneficial for improving college students’ perceptions and selections of targeted healthful foods in the dining hall and may improve overall eating behaviors of college students.     

Braided geographies: bordered forms and cross-border formations in refugee comics

ABSTRACT

This article offers a close analysis of a trilogy of ‘refugee comics’ entitled ‘A Perilous Journey’, which were produced in 2015 by the non-profit organisation PositiveNegatives, to conceive of comics as a bordered form able to establish alternative cross-border formations, or ‘counter-geographies’, as it calls them. Drawing on the work of Martina Tazzioloi, Thierry Groensteen, Jason Dittmer, Michael Rothberg and others, the article argues that it is by building braided, multi-directional relationships between different geographic spaces, both past and present, that refugee comics realise a set of counter-geographic and potentially decolonising imaginaries. Through their spatial form, refugee comics disassemble geographic space to reveal counter-geographies of multiple synchronic and diachronic relations and coformations, as these occur between different regions and locations, and as they accumulate through complex aggregations of traumatic and other affective memories. The article contends that we need an interdisciplinary combination of the critical reading skills of humanities scholars and the rigorous anthropological, sociological and theoretical work of the social sciences to make sense of the visualisation of these counter-geographic movements in comics. It concludes by showing how the counter-geographies visualised by refugee comics can subvert the geopolitical landscape of discrete nation-states and their territorially bound imagined communities.