1. Introduction and Overview. 2. Detecting Influential Observations and Outliers. 3. Detecting and Assessing Collinearity. 4. Applications and Remedies. 5. Research Issues and Directions for Extensions. Bibliography. Author Index. Subject Index.

Regression Diagnostics: Identifying Influential Data and Sources of Collinearity

The peak age of onset for many psychiatric disorders is adolescence, a time of remarkable physical and behavioural changes. The processes in the brain that underlie these behavioural changes have been the subject of recent investigations. What do we know about the maturation of the human brain during adolescence? Do structural changes in the cerebral cortex reflect synaptic pruning? Are increases in white-matter volume driven by myelination? Is the adolescent brain more or less sensitive to reward? Finding answers to these questions might enable us to further our understanding of mental health during adolescence.

Why do many psychiatric disorders emerge during adolescence

Background: Many alcohol research questions require methods that take a person-centered approach because the interest is in finding heterogeneous groups of individuals, such as those who are susceptible to alcohol dependence and those who are not. A person-centered focus also is useful with longitudinal data to represent heterogeneity in developmental trajectories. In alcohol, drug, and mental health research the recognition of heterogeneity has led to theories of multiple developmental pathways. Methods: This paper gives a brief overview of new methods that integrate variable- and person-centered analyses. Methods discussed include latent class analysis, latent transition analysis, latent class growth analysis, growth mixture modeling, and general growth mixture modeling. These methods are presented in a general latent variable modeling framework that expands traditional latent variable modeling by including not only continuous latent variables but also categorical latent variables. Results: Four examples that use the National Longitudinal Survey of Youth (NLSY) data are presented to illustrate latent class analysis, latent class growth analysis, growth mixture modeling, and general growth mixture modeling. Latent class analysis of antisocial behavior found four classes. Four heavy drinking trajectory classes were found. The relationship between the latent classes and background variables and consequences was studied. Conclusions: Person-centered and variable-centered analyses typically have been seen as different activities that use different types of models and software. This paper gives a brief overview of new methods that integrate variable- and person-centered analyses. The general framework makes it possible to combine these models and to study new models serving as a stimulus for asking research questions that have both person- and variable-centered aspects.

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Integrating Person-Centered and Variable-Centered Analyses: Growth Mixture Modeling With Latent Trajectory Classes

We investigate whether superior performance on corporate social responsibility (CSR) strategies leads to better access to finance. We hypothesize that better access to finance can be attributed to (1) reduced agency costs due to enhanced stakeholder engagement and (2) reduced informational asymmetry due to increased transparency. Using a large cross-section of firms, we find that firms with better CSR performance face significantly lower capital constraints. We provide evidence that both better stakeholder engagement and transparency around CSR performance are important in reducing capital constraints. The results are further confirmed using several alternative measures of capital constraints, a paired analysis based on a ratings shock to CSR performance, an instrumental variables approach, and a simultaneous equations approach. Finally, we show that the relation is driven by both the social and environmental dimension of CSR. Copyright © 2013 John Wiley & Sons, Ltd.

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Corporate social responsibility and access to finance

We examine the effect of corporate social responsibility (CSR) on the cost of equity capital for a large sample of US firms. Using several approaches to estimate firms’ ex ante cost of equity, we find that firms with better CSR scores exhibit cheaper equity financing. In particular, our findings suggest that investment in improving responsible employee relations, environmental policies, and product strategies contributes substantially to reducing firms’ cost of equity. Our results also show that participation in two “sin” industries, namely, tobacco and nuclear power, increases firms’ cost of equity. These findings support arguments in the literature that firms with socially responsible practices have higher valuation and lower risk.

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Does Corporate Social Responsibility Affect the Cost of Capital

Sequential stages of involvement in alcohol and/or cigarettes, marijuana, other illicit drugs and medically prescribed psychoactive drugs from adolescence to adulthood are investigated in a longitudinal cohort that has been followed from ages 15 to 35. Alternative models of progression are tested for their goodness of fit. Four stages are identified: that of legal drugs, alcohol or cigarettes; marijuana; illicit drugs other than marijuana; and medically prescribed drugs. Whereas progression to illicit drugs among men is dependent upon prior use of alcohol, among women either cigarettes or alcohol is a sufficient condition for progression to marijuana. Age of onset and frequency of use at a lower stage of drug use are strong predictors of further progression.

Stages of progression in drug involvement from adolescence to adulthood: further evidence for the gateway theory.

Legal protection of investors, corporate governance, and the cost of equity capital

Legal Protection of Investors, Corporate Governance, and the Cost of Equity Capital

Rates of nicotine dependence vary in different sociodemographic groups in the population. These group differences remain to be understood. The objective of this study is to specify the relationship between cigarette consumption and nicotine dependence and whether group differences are explained by quantity smoked or differential sensitivity to nicotine. The data used derived from National Household Surveys on Drug Abuse (1991-1993), multistage area probability samples of the US population 12 years old and over, and anonymous structured household interviews, considering subjects who were last-month smokers (12,550 White, 4903 Black, 4839 Hispanic). The main outcome measure was last-year nicotine dependence based on symptoms of dependence and drug-related problems approximating DSM-IV dependence criteria. Rates are higher among females than males, Whites than minorities and the lowest among older adults. Dependence rates increase sharply up to half a pack of cigarettes smoked per day. At higher quantities, the increased risk for dependence is minimal. The higher rate of dependence among females than males results from a greater number of symptoms at the same quantity smoked. The similarity of adolescent and middle-adult rates results from the fact that adolescents smoke significantly fewer cigarettes than adults, but experience higher rates of dependence at the same levels of use. Although adults 50 and over are the heaviest smokers, they experience the lowest rates of dependence because of hypothesized lower sensitivity to increased quantity of nicotine intake. The higher rates among Whites than Blacks appear to result from heavier smoking and greater sensitivity to nicotine effects. It was concluded that adolescents, women and Whites are particularly vulnerable to becoming dependent on nicotine. Group-specific thresholds may be more appropriate criteria than an absolute threshold to define the risk for nicotine dependence.

Kevin C.W. Chen

Papers

Stages of progression in drug involvement from adolescence to adulthood: further evidence for the gateway theory.

Legal protection of investors, corporate governance, and the cost of equity capital

Legal Protection of Investors, Corporate Governance, and the Cost of Equity Capital

Extent of smoking and nicotine dependence in the United States: 1991–1993

Default on Debt Obligations and the Issuance of Going-concern Opinions