African Americans and municipal employment: A test of two perspectives

A survey of the extant literature addressing the factors that drive African American municipal employment offers two broad types of explanations: (1) Black political power and (2) institutional. A comparative assessment of the performance of each of these explanations fills a gap in the literature by illuminating the differences of these distinct perspectives when it comes to employment of Blacks in the public sector. Focusing on six Florida cities from 1960 to 2000, this study tests the predictive power of each of these explanations comparatively for four city departments. The findings indicate that the Black political power explanation performs better than the institutional explanation as a predictor of Black employment.     

Detecting parameter shift in garch models

This paper applies recent theories of testing for parameter constancy to the conditional variance in a GARCH model. The supremum Lagrange multiplier test for conditional Gaussian GARCH models and its robustified variants are discussed. The asymptotic null distribution of the test statistics are derived from the weak convergence of the scores, and the critical values from the hitting probability of squared Bessel process.

Monte Carlo studies on the finite sample size and power performance of the supremum LM tests are conducted. Applications of these tests to S&P 500 indicate that the hypothesis of stable conditional variance parameters can be rejected.     

Socialization of emotion: Pathway to preschoolers' emotional and social competence

Aspects of 47 preschoolers'emotional competence—their patterns of emotional expressiveness and reactions to others' emotion displays—were observed in two settings, with mother and with peers, and their general social competence was rated by their preschool teachers. Intrapersonal and interpersonal (i.e., socialization correlates of children's emotional competence were identified, and a causal model incorporating direct and indirect influences on social competence was evaluated. Maternal patterns of expressiveness, reactions to children's emotion displays, and self-reported affective environment were associated with children's emotional competence in the preschool. Children's emotional competence with mother predicted their emotional competence in the preschool somewhat less strongly, suggesting that emotional competence may differ according to the interpersonal relationship studied. Taken as a whole, findings reassert the importance of the domain of emotional expression to the development of social competence.Reprint requests can be sent to the author, Department of Psychology, George Mason University, 4400 University Drive, Fairfax, VA 22030. Grateful acknowledgment goes to the mothers and children who so clearly expressed and reacted to emotions; thanks also are due to Christine Alban, Joanne Ayyash, Michael Casey, Elizabeth Couchoud, Huynh Dung, Merlina Hemingway, Soueang Lay, Vanna Nguyen, Emilianne Slayden and Kimberly Sproul, as well as the director and teachers of the Project for the Study of Young Children. An earlier version of this material was presented at the 1991 Biennial Meetings of the Society for Research in Child Development, Seattle, WA. University support from Grants #2-10150, 2-10176 and 2-10073 also made the research possible.     

A Tabu Search Heuristic for the Location of Multi-Type Protection Devices on Electrical Supply Tree Networks

The problem of determining the number of multi-type protection devices and their locations on electrical supply tree networks with subtree dependency is investigated. The aim is to reduce the amount of inconvenience caused to customers that are affected by any given fault on the networks. An appropriate implementation of tabu search is proposed. We exploit a variable neighborhood and a soft aspiration level, and we embed a data structure and reduction tests into the search to speed up the process. Computational tests are performed on randomly generated electrical tree networks varying in size and branch complexity with encouraging results.     

Significance of the Dermal Route of Exposure to Risk Assessment

The skin is a route of exposure that needs to be considered when conducting a risk assessment. It is necessary to identify the potential for dermal penetration by a chemical as well as to determine the overall importance of the dermal route of exposure as compared with inhalation or oral routes of exposure. The physical state of the chemical, vapor or liquid, the concentration, neat or dilute, and the vehicle, lipid or aqueous, is also important. Dermal risk is related to the product of the amounts of penetration and toxicity. Toxicity involves local effects on the skin itself and the potential for systemic effects. Dermal penetration is described in large part by the permeability constant. When permeability constants are not known, partition coefficients can be used to estimate a chemical's potential to permeate the skin. With these concepts in mind, a tiered approach is proposed for dermal risk assessment. A key first step is the determination of a skin-to-air or skin-to-medium partition coefficient to estimate a potential for dermal absorption. Building a physiologically-based pharmacokinetic (PBPK) model is another step in the tiered approach and is useful prior to classical in vivo toxicity tests. A PBPK model can be used to determine a permeability constant for a chemical as well as to show the distribution of the chemical systemically. A detailed understanding of species differences in the structure and function of the skin and how they relate to differences in penetration rates is necessary in order to extrapolate animal data from PBPK models to the human. A study is in progress to examine anatomical differences for four species.     

EVALUATING CHANGES IN THE DISTRIBUTION OF CAPITAL WEALTH

A small-scale general equilibrium model in which the distribution of capital wealth is a key parameter is employed to examine the potential economic consequences of greater capital wealth equality. Every performance indicator examined – aggregate income, consumption equality, social welfare in the sum-of-utilities sense, and aggregate saving –is improved by greater capital wealth equality. However, the bottom-line social welfare gain, relative to the present high-inequality situation – even from the maximum achievable level of complete equality in capital wealth distribution – would be numerically rather modest.     

Lumpers and Splitters: The Public Opinion Information that Politicians Collect and Use

Are the decisions of American policymakers informed by generaltrends in the public’s ideology or by the public’spolicy-specific preferences? In this article we discuss twoexplanations for the types of public opinion information thatpoliticians collect and use. Using a unique data set of privatepolls from the White House of Richard Nixon, we find that whenopinion data on specific policies were available, the presidentrelied on them and not on general ideology data. On less importantissues, however, we find that the president often chose notto collect policy-specific data and instead relied on generalideology data. The differential collection and use of informationby policymakers reflect varying strategic calculations. Theyalso have profound implications for representative democracyand the demands placed on citizens and governors.