Pivotal Statistics for Testing Structural Parameters in Instrumental Variables Regression

We propose a novel statistic for conducting joint tests on all the structural parameters in instrumental variables regression. The statistic is straightforward to compute and equals a quadratic form of the score of the concentrated log–likelihood. It therefore attains its minimal value equal to zero at the maximum likelihood estimator. The statistic has a χ² limiting distribution with a degrees of freedom parameter equal to the number of structural parameters. The limiting distribution does not depend on nuisance parameters. The statistic overcomes the deficiencies of the Anderson–Rubin statistic, whose limiting distribution has a degrees of freedom parameter equal to the number of instruments, and the likelihood based, Wald, likelihood ratio, and Lagrange multiplier statistics, whose limiting distributions depend on nuisance parameters. Size and power comparisons reveal that the statistic is a (asymptotic) size–corrected likelihood ratio statistic. We apply the statistic to the Angrist–Krueger (1991) data and find similar results as in Staiger and Stock (1997).     

Reliability Analysis for Hazardous Waste Treatment Processes

The reliability of a treatment process is addressed in terms of achieving a regulatory effluent concentration standard and the design safety factors associated with the treatment process. This methodology was then applied to two aqueous hazardous waste treatment processes: packed tower aeration and activated sludge (aerobic) biological treatment. The designs achieving 95 percent reliability were compared with those designs based on conventional practice to determine their patterns of conservatism. Scoping-level treatment costs were also related to reliability levels for these treatment processes. The results indicate that the reliability levels for the physical/chemical treatment process (packed tower aeration) based on the deterministic safety factors range from 80 percent to over 99 percent, whereas those for the biological treatment process range from near 0 percent to over 99 percent, depending on the compound evaluated. Increases in reliability per unit increase in treatment costs are most pronounced at lower reliability levels (less than about 80 percent) than at the higher reliability levels (greater than 90 percent, indicating a point of diminishing returns. Additional research focused on process parameters that presently contain large uncertainties may reduce those uncertainties, with attending increases in the reliability levels of the treatment processes.     

The Relation Between Popularity and Aggressive,Destructive, and Norm‐Breaking Behaviors: Moderating Effects of Athletic Abilities,Physical Attractiveness,and Prosociality

The aim of this study was to examine the relations between popularity and different types of aggressive, destructive, and norm‐breaking behaviors in a large cross‐sectional sample of adolescents (N=3,312, M age=13.60). We were interested in the extent to which the relations of these behaviors with popularity were moderated by positive features (i.e., athletic abilities, physical attractiveness, and prosociality). From a goal‐framing perspective, it was argued that positive features evoke positive affect, which in turn enhances the positive impact of aggressive, destructive, and norm‐breaking behaviors on popularity. The results supported our notion that these latter behaviors are especially related to popularity in adolescents who also exhibit positive features.     

Mapping Invasive Species Risks with Stochastic Models: A Cross-Border United States-Canada Application for Sirex noctilio Fabricius

Nonindigenous species have caused significant impacts to North American forests despite past and present international phytosanitary efforts. Though broadly acknowledged, the risks of pest invasions are difficult to quantify as they involve interactions between many factors that operate across a range of spatial and temporal scales: the transmission of invading organisms via various pathways, their spread and establishment in new environments. Our study presents a stochastic simulation approach to quantify these risks and associated uncertainties through time in a unified fashion. We outline this approach with an example of a forest pest recently detected in North America, Sirex noctilio Fabricius. We simulate new potential entries of S. noctilio as a stochastic process, based on recent volumes of marine shipments of commodities from countries where S. noctilio is established, as well as the broad dynamics of foreign marine imports. The results are then linked with a spatial model that simulates the spread of S. noctilio within the geographical distribution of its hosts (pines) while incorporating existing knowledge about its behavior in North American landscapes. Through replications, this approach yields a spatial representation of S. noctilio risks and uncertainties in a single integrated product. The approach should also be appealing to decisionmakers, since it accounts for projected flows of commodities that may serve as conduits for pest entry. Our 30-year forecasts indicate high establishment probability in Ontario, Quebec, and the northeastern United States, but further southward expansion of S. noctilio is uncertain, ultimately depending on the impact of recent international treatment standards for wood packing materials.     

The role of relationships in labor markets for the popular arts and its impact on product quality

While utilizing social networks is common in labor markets and may benefit both firms and laborers, social networks are argued to be unusually important in the popular arts. Prior work in economics on the role of relationships in labor markets has generally focused on the benefits and not the costs. This paper takes a different approach by focusing on both costs and benefits, by examining a specific market where relationships are particularly important. This paper argues that in addition to reducing diversity and creating inherent inequalities, excessive reliance on networks can lead to higher agency costs and lower product quality.     

Adolescent Women's Recommendations for Enhanced Parent-Adolescent Communication About Sexual Behavior

Family communication about adolescent sexual health and behavior promotes adolescent health and family connectedness. However, few studies seek the perspective of adolescents regarding their recommended strategies for family communication. Findings of a survey of female adolescent family planning patients (n = 249) indicated adolescent recommendations for better family communication included treat teen as an equal, 63%; increase parental knowledge about lifestyle and peer pressures, 61%, and improve parental listening skills, 61%. There were no statistically significant differences according to age, pregnancy history, or school enrollment status for suggested strategies for improved communication with parents. Sexually active adolescent daughters expressed interest in maintaining family connectedness and support with increased time for family activities as well as increased quality and quantity of dialogue between the adolescent girl and her parents.     

The Inevitability of Client Alienation: a Counter Argument*

We argue that earlier characterizations of clients are inadequate in considering the complexities of organizational-client relations. Some writers assume that client alienation is an inevitable outcome of certain types of bureaucratic structures (e.g., welfare). We show that in the face of large service organizations, some clients fail to experience significant amounts of alienation by forcing organizations to vacate traditional bureaucratic forms and processes. The lack of alienation is accounted for by clients' expertise, political organization, and their access to bureaucracy.     

Trajectories of Gambling During Adolescence

This study aimed at empirically identifying groups of adolescents with distinct longitudinal trajectories of gambling involvement and validating these groups by comparing them with respect to correlates. 903 low SES boys were followed annually from age 11 to 16 years. Three groups were found: an early-onset high-level chronic group, a late-onset high-level group, and a low gambler group. The Chronic group and the Low group consistently differed on teacher-rated inhibition (i.e., anxiety) during childhood and early adolescence. They also differed on concurrent teacher and self ratings of disinhibition (i.e., impulsivity), while the Late Onset group appeared to lie in between these groups. Compared to the Low group, both high groups subsequently had elevated scores on later gambling related problems.     

Inferences concerning interpersonal choices given anonymously

It may be difficult or impossible to make a reliable empirical investigation of an unknown network of interpersonal choices or contacts if these are in some respect sensitive for the individuals involved. We consider how choice data given anonymously can be used to reveal various features of the network. Using tools from statistical decision theory and information theory we can determine risks and capacities of disclosing choice data, the graph structure of choice data and its numbers of loops and mutuals. We give some general results, illustrate the combinatorial complexity of the problem and comment upon the computational difficulties.