Euler(p,q) Processes and Their Application to Non Stationary Time Series with Time Varying Frequencies

We introduce Euler(p, q) processes as an extension of the Euler(p) processes for purposes of obtaining more parsimonious models for non stationary processes whose periodic behavior changes approximately linearly in time. The discrete Euler(p, q) models are a class of multiplicative stationary (M-stationary) processes and basic properties are derived. The relationship between continuous and discrete mixed Euler processes is shown. Fundamental to the theory and application of Euler(p, q) processes is a dual relationship between discrete Euler(p, q) processes and ARMA processes, which is established. The usefulness of Euler(p, q) processes is examined by comparing spectral estimation with that obtained by existing methods using both simulated and real data.     

Multiple Book Review: Four Perspectives on Human Natures: Genes,Cultures, and the Human Prospect. Paul R. Ehrlich. Washington,DC: Island Press, 2000, 531 pp.

Population and Environment -     

Accessibility to micro-finance services by people with disabilities in Bushenyi District,Uganda

The Poverty Reduction Strategy of the Ugandan Government identified provision of microfinance as one of its interventions. Despite the known connection between poverty and people with disabilities, it remains unclear to what extent this intervention includes or accommodates them. This study seeks to gain a better understanding of how people with physical and sensory disabilities access existing microfinance services in the Bushenyi District of Uganda. Qualitative and quantitative methodologies are used. The findings suggest that people with disabilities are not necessarily denied access to microfinance if they meet the desired requirements. These relate to adequate savings or collateral and perceived trustworthiness. These are seen to be key determinants of success and can be linked to impaired functioning relating to limited mobility, distance, poorer access to information and disabled people’s own negative attitudes. Increasing access and utilization of microfinance services by people with disabilities requires formulation of financial policies that accord them special consideration. At the same time, improvement is needed in the knowledge, attitudes and skills of the people with disabilities themselves and also microfinance providers.     

Editorial

The Analysis of Verbal Behavior -     

Guiding Resource Allocations Based on Terrorism Risk

Establishing tolerable levels of risk is one of the most contentious and important risk management decisions. With every regulatory or funding decision for a risk management program, society decides whether or not risk is tolerable. The Urban Area Security Initiative (UASI) is a Department of Homeland Security (DHS) grant program designed to enhance security and overall preparedness to prevent, respond to, and recover from acts of terrorism by providing financial assistance for planning, equipment, training, and exercise needs of large urban areas. After briefly reviewing definitions of terrorism risk and rationales for risk-based resource allocation, this article compares estimates of terrorism risk in urban areas that received UASI funding in 2004 to other federal risk management decisions. This comparison suggests that UASI allocations are generally consistent with other federal risk management decisions. However, terrorism risk in several cities that received funding is below levels that are often tolerated in other risk management contexts. There are several reasons why the conclusions about terrorism risk being de minimis in specific cities should be challenged. Some of these surround the means used to estimate terrorism risk for this study. Others involve the comparison that is made to other risk management decisions. However, many of the observations reported are valid even if reported terrorism risk estimates are several orders of magnitude too low. Discussion of resource allocation should be extended to address risk tolerance and include explicit comparisons, like those presented here, to other risk management decisions.     

Estimating the proportion of true null hypotheses, with application to DNA microarray data

Summary.  We consider the problem of estimating the proportion of true null hypotheses, π ₀, in a multiple-hypothesis set-up. The tests are based on observed p -values. We first review published estimators based on the estimator that was suggested by Schweder and Spjøtvoll. Then we derive new estimators based on nonparametric maximum likelihood estimation of the p -value density, restricting to decreasing and convex decreasing densities. The estimators of π ₀ are all derived under the assumption of independent test statistics. Their performance under dependence is investigated in a simulation study. We find that the estimators are relatively robust with respect to the assumption of independence and work well also for test statistics with moderate dependence.     

Intersecting Lorenz Curves, the Degree of Downside Inequality Aversion, and Tax Reforms

This paper clarifies the conceptual distinction of downside inequality aversion (or transfer sensitivity) as a normative criterion for judging income distributions from the Pigou-Dalton principle of transfers. We show that when the Lorenz curves of two income distributions intersect, how the change from one distribution to the other is judged by an inequality index exhibiting downside inequality aversion often depends on the relative strengths of its downside inequality aversion and inequality aversion. For additive inequality indices or their monotonic transformations, a measure characterizing the strength of an index’s downside inequality aversion against its inequality aversion is shown to determine the ranking by the index of two distributions whose Lorenz curves cross once. The precise condition under which the same result generalizes to the case of multiple-crossing Lorenz curves is also identified. The results are particularly useful in understanding the distributional impact of tax reforms. I received exceptionally helpful comments from Mike Hoy, Peter Lambert, the Editor, Buhong Zheng, and an anonymous referee. The remaining errors and shortcomings are my own – W.H. Chiu     

The Roles of Group Membership, Beliefs, and Norms in Ecological Risk Perception

Variability in ecological risk perceptions was investigated by surveying members of four stakeholder groups commonly involved in environmental policy debates. Fifty-six individuals from government, industry, environmental, and general-public groups completed a risk-perception survey in which they evaluated 34 environmental hazards on 17 attributes and also evaluated the riskiness and acceptability of each hazard. In addition, participants reported their environmental beliefs and norms using Dunlap et al.'s revised New Ecological Paradigm Scale and modified versions of Schwartz's Awareness of Consequences and Personal Norms Scales. Group membership was predictive of participants' scores on the belief and norm scales. Factor analysis of attribute ratings (averaged across participants) revealed the anticipated three oblique factors: ecological impacts, scientific understanding, and aesthetic impacts. Factor patterns were very similar for the four stakeholder groups. Factors from the aggregate analysis were predictive of individuals' riskiness judgments, but these relationships were moderated by participants' group membership, beliefs, and norms. Compared to members of other groups, members of the general public placed less emphasis on ecological impacts and more emphasis on the other two factors when judging the ecological riskiness of hazards. To our knowledge, these results represent the first formal tests of interactions between hazard characteristics and participant characteristics in determining riskiness judgments, and illustrate how traditional psychometric analyses can be successfully coupled with individual-difference measures to improve the understanding of risk perception.     

Direct and indirect impacts of environmental factors on migration in Burkina Faso: application of structural equation modelling

Population and Environment - In the prolific literature on the impact of environment on migration, direct and indirect effects are often mentioned but rarely estimated separately. We use structural...