Demography of disaster: Population estimates after hurricane Andrew

Hurricane Andrew blasted through the southern tip of Florida in August 1992, damaging or destroying tens of thousands of homes and forcing hundreds of thousands of persons to move at least temporarily to different places of residence. The hurricane not only disrupted the lives of many Floridians, but destroyed the statistical basis for producing local population estimates in South Florida as well. These estimates are used for many types of decision-making, from the distribution of state revenue-sharing dollars to choosing sites for fast-food restaurants. This article describes the estimation problems created by the hurricane and how those problems were resolved through the use of existing data sources and the collection of new types of data. It closes with a discussion of several conceptual, methodological and procedural issues that will have to be faced in virtually any attempt to estimate the demographic consequences of natural disasters.An earlier version of this paper was presented at the 1994 annual meeting of the Population Association of America, Miami, Florida, USA.     

Latino,Asian, and black segregation in U.S. metropolitan areas: Are multiethnic metros different*

This study examines 1990 residential segregation levels and 1980–1990 changes in segregation for Latinos, Asians, and blacks in U.S. metropolitan areas. It also evaluates the effect of emerging multiethnic metropolitan area contexts for these segregation patterns. While black segregation levels are still well above those for Latinos and Asians, there is some trend toward convergence over the decade. More than half of the areas increased their Latino segregation levels over the 1980s, and almost three-fourths increased their Asian segregation levels. In contrast, black segregation levels decreased in 88%ofmetropolitan areas. Multiethnic metropolitan area context is shown to be important for internal segregation dynamics. Black segregation levels are lower, and were more likely to decline in multiethnic metropolitan areas and when other minority groups grew faster than blacks. Latino segregation was also more likely to decline in such areas, and declines in both Latino and Asian segregation were greater when other minority groups were growing. These findings point up the potential for greater mixed-race and mixed-ethnicity coresidence in the neighborhoods of multiethnic metropolitan areas.     

THE CONVERGENCE RATE OF SEQUENTIAL FIXED-WIDTH CONFIDENCE INTERVALS FOR REGULAR FUNCTIONALS

Let X₁X₂,.be i.i.d. random variables and let U_n= (n r)^-1S?^(n,r) h (X_i1,., X_ir,) be a U-statistic with EU_n= v, v unknown. Assume that g(X₁) =E[h(X₁,.,X_r) - v |X₁]has a strictly positive variance s?². Further, let a be such that φ(a) - φ(-a) =α for fixed α, 0 < α < 1, where φ is the standard normal d.f., and let S²_n be the Jackknife estimator of n Var U_n. Consider the stopping times N(d)= min {n: S²_n: + n^-1≤²a^-2},d > 0, and a confidence interval for v of length 2d,of the form I_n,d= [U_n,-d, Un + d]. We assume that Var U_n is unknown, and hence, no fixed sample size method is available for finding a confidence interval for v of prescribed width 2d and prescribed coverage probability α Turning to a sequential procedure, let I_N(d),d be a sequence of sequential confidence intervals for v. The asymptotic consistency of this procedure, i.e. lim_{d → 0}P(v ∈ I_N(d),d)=α follows from Sproule (1969). In this paper, the rate at which |P(v ∈ I_N(d),d) converges to α is investigated. We obtain that |P(v ∈ I_N(d),d) - α| = 0 (d^{1/2-(1+k)/2(1+m)}), d → 0, where K = max {0,4 - m}, under the condition that E|h(X₁, X_r)|^m < ∞m > 2. This improves and extends recent results of Ghosh & DasGupta (1980) and Mukhopadhyay (1981).     

Migration differentials by education and occupation: Trends and variations

The effects of education on current migration propensities in the United States are examined for each age group, and an estimate is made of how these age-specific differentials cumulate over a lifetime in determining the number of times that individuals at different educational levels can expect to move over the course of their lives. The independent effects of age, education, and occupation are also examined. Two other sections investigate trends in educational selectivity of migration in the United States and international comparisons of occupational differences in migration.     

Boards of directors: control and decision making in Canadian corporations*

Les statuts légaux spécifient que les corporations doivent être dirigées par un conseil d'administrateurs. Cette étude examine le rôle des directorâts en pouvoir et en contrôle dans un échantillon de corporations manufacturières et découvre, en général, que les conseils n'ont aucune influence sur les prises de décisions. La possession corporative et la composition des conseils sont reconnus comme d'importants facteurs qui affectent les structures de contrôles. Si la possession est concentree sur une base origine-filiale, le contrôle tend àêtre levé par l'enchaînement de gérance. Quand la possession est largement concentrée chez les directeurs, ceux-ci sont en lieu de retenir le contrôle. Si la possession est établie par des actionnaires qui ne sont pas les directeurs, la directive aura des degrés variants de contrôle dans les prises de décisions, dépendant sur la concentration de cette possession. Si la directive contient des courtiers, il est plus possible d'y avoir une fonction de contrôle dans les prises de décisions que quand la corporation est composée entièrement d'initiés. Legal statutes specify that corporations shall be managed by a board of directors. This study examines the role of directorates in power and control in a sample of manufacturing corporations and finds, in general, that most boards are not influential in decision making. Corporate ownership and board composition are found to be important factors affecting control patterns. If ownership is concentrated on a parent-subsidiary basis, control tends to be exercised through management links. When ownership is largely by managers, they are likely to retain control. If ownership is by nonmanager shareholders, then the board will have varying degrees of control in decision making, depending on the concentration of that ownership. If the board contains outsiders, then it is more likely to have a control function in corporate decision making than when it is composed solely of insiders.