Risk of Extreme Events in Multiobjective Decision Trees Part 1. Severe Events

Earlier work with decision trees identified nonseparability as an obstacle to minimizing the conditional expected value, a measure of the risk of extreme events, by the well-known method of averaging out and folding back. This first of two companion papers addresses the conditional expected value that is defined as the expected outcome assuming the exceedance of a threshold β, where β is preselected by the decision maker. An approach is proposed to overcome the need to evaluate all policies in order to identify the optimal policy. The approach is based on the insight that the conditional expected value is separable into two constituent elements of risk and can thus be optimized along with other objectives, including the unconditional expected value of the outcome, by using a multiobjective decision tree. An example of sequential decision making for improving highway capacity is given.     

FPT-algorithms for some problems related to integer programming

This paper studies a new version of the location problem called the mixed center location problem. Let P be a set of n points in the plane. We first consider the mixed 2-center problem, where one of the centers must be in P, and we solve it in \(O(n^2\log n)\) time. Second, we consider the mixed k-center problem, where m of the centers are in P, and we solve it in \(O(n^{m+O(\sqrt{k-m})})\) time. Motivated by two practical constraints, we propose two variations of the problem. Third, we present a 2-approximation algorithm and three heuristics solving the mixed k-center problem (\(k>2\)).     

New perspectives on the governance of executive compensation: an examination of the role and effect of compensation consultants

We develop a multi-theoretic approach, drawing on economic, institutional, managerial power and social comparison literatures to explain the role of the external compensation consultant in the top management pay setting institutional field. Taking advantage of recent disclosure requirements in the UK, we collect data on compensation consultant use in 232 large companies. We show that consultants are a prevalent part of the CEO pay setting scene, and document evidence of all advisor use. Our econometric results show that consultant use is associated with firm size and the equity pay mix. We also show that CEO pay is positively associated with peer firms that share consultants, with higher board and consultant interlocks, and some evidence that where firms supply other business services to the firm, CEO pay is greater.     

A cross-cultural comparison of death anxiety: a brief note

Data are reported from samples of undergraduates around the world who have been administered Templer's Death Anxiety Scale. Data from 24 American samples and from 16 nations were identified. Strong sex differences were found and an association between the scores of men and women.     

Aggregation and Market Demand: An Exterior Differential Calculus Viewpoint

We analyze under which conditions a given vector field can be disaggregated as a linear combination of gradients. This problem is typical of aggregation theory, as illustrated by the literature on the characterization of aggregate market demand and excess demand. We argue that exterior differential calculus provides very useful tools to address these problems. In particular, we show, using these techniques, that any analytic mapping in Rⁿ satisfying Walras Law can be locally decomposed as the sum of n individual, utility-maximizing market demand functions. In addition, we show that the result holds for arbitrary (price-dependent) income distributions, and that the decomposition can be chosen such that it varies continuously with the mapping. Finally, when income distribution can be freely chosen, then decomposition requires only n/2 agents.     

Residential Building Codes,Affordability, and Health Protection: A Risk-Tradeoff Approach

Residential building codes intended to promote health and safety may produce unintended countervailing risks by adding to the cost of construction. Higher construction costs increase the price of new homes and may increase health and safety risks through income and stock effects. The income effect arises because households that purchase a new home have less income remaining for spending on other goods that contribute to health and safety. The stock effect arises because suppression of new-home construction leads to slower replacement of less safe housing units. These countervailing risks are not presently considered in code debates. We demonstrate the feasibility of estimating the approximate magnitude of countervailing risks by combining the income effect with three relatively well understood and significant home-health risks. We estimate that a code change that increases the nationwide cost of constructing and maintaining homes by $150 (0.1% of the average cost to build a single-family home) would induce offsetting risks yielding between 2 and 60 premature fatalities or, including morbidity effects, between 20 and 800 lost quality-adjusted life years (both discounted at 3%) each year the code provision remains in effect. To provide a net health benefit, the code change would need to reduce risk by at least this amount. Future research should refine these estimates, incorporate quantitative uncertainty analysis, and apply a full risk-tradeoff approach to real-world case studies of proposed code changes.     

Research on stalking: what do we know and where do we go?

Findings of the article in this two-volume series on stalking are reviewed. Building on the findings of the National Violence Against Women Survey (Tjaden & Thoennes, 1998), this series of studies adds to the literature in defining and measuring stalking behaviors. Repeated stalking victimization is reported by up to 62% of young adults, although frequencies depend on the sample and the precise definition used. Self-definitions of stalking victimization may be quite different from legal definitions. Although the majority of legally defined stalkers (where victim fear is a key component) are men stalking women, studies utilizing other definitions find many more women as stalkers, with no significant gender differences in many studies. In many cases, it does appear that stalking is one part of a larger pattern of relationship physical and psychological abuse. Data on emotional reactions and coping strategies of victims are also reviewed, along with findings on characteristics of stalkers.     

A methodological strategy for a one-number census in the UK

As a result of lessons learnt from the 1991 census, a research programme was set up to seek improvements in census methodology. Underenumeration has been placed top of the agenda in this programme, and every effort is being made to achieve as high a coverage as possible in the 2001 census. In recognition, however, that 100% coverage will never be achieved, the one-number census (ONC) project was established to measure the degree of underenumeration in the 2001 census and, if possible, to adjust fully the outputs from the census for that undercount. A key component of this adjustment process is a census coverage survey (CCS). This paper presents an overview of the ONC project, focusing on the design and analysis methodology for the CCS. It also presents results that allow the reader to evaluate the robustness of this methodology.     

Immigrant incorporation in the garment industry of Los Angeles

This study expands immigrant social network theory and examined employment patterns in the garment industry in Los Angeles, California, among Latino workers employed by Asian immigrant entrepreneurs. The study determined that a large percentage of immigrant employees found their jobs through the immigrant economy. Entrepreneurship increased the supply of local jobs and expanded the economy at destination at no expense to natives. Immigrant entrepreneurs bought firms from nonimmigrant owners or started new ones with an immigrant labor supply. Massey's index is flawed due to its exclusion of the role of entrepreneurs. Migration networks facilitate entrepreneurship, but some ethnic groups have fewer entrepreneurs, such as Mexicans and Central Americans. A 1993 Los Angeles survey identified 3642 garment factories in its county. Mean employment was 27.1 persons. The garment industry was the 4th largest industry in the area in 1996, with 98,700 employees. It represented 6% of all wage and salary employees in the City and 5.5% of the immigrant labor force in the County in 1990. 93% of garment workers in 1990 were immigrants. It is estimated that 51% of garment factory owners were Asians; most employees were Latinos. Census figures on sewing machine operators indicated 47.3% of owners were Whites and 42.45 were Asians. 53.3% of employees were other ethnic groups, 14.5% were Asians, and 32.2% were Whites. It is estimated that 47.2% of total employment was due to the immigration economy. 71.5% of the total employment in the garment industry was in the immigrant sector.