Changing fuel use behavior: The Pittsburgh smoke control movement, 1940–1950

Local policy development in Pittsburgh brought about cleaner air by influencing change in the household use of fuel and combustion equipment. By a combination of media campaigns, voluntary organizations, technical advisers, and business and labor leaders, the public was convinced of the necessity to reduce air pollution. The unique aspect is that the public accepted the costs of a long-range policy decision through education and persuasion.     

Variable selection and estimation in high‐dimensional models

Models with high‐dimensional covariates arise frequently in economics and other fields. Often, only a few covariates have important effects on the dependent variable. When this happens, the model is said to be sparse. In applications, however, it is not known which covariates are important and which are not. This paper reviews methods for discriminating between important and unimportant covariates with particular attention given to methods that discriminate correctly with probability approaching 1 as the sample size increases. Methods are available for a wide variety of linear, nonlinear, semiparametric and nonparametric models. The performance of some of these methods in finite samples is illustrated through Monte Carlo simulations and an empirical example.     

Testing and the Composition of the Labor Pool

We consider a continuous‐time labor matching model with endogenous separation. Firms initially lack information about the quality of workers with whom they are matched. They acquire information both from pre‐employment testing and, in the case in which a labor relationship is established, on‐the‐job performance. Testing provides a signal of a worker's quality. A firm can pick the accuracy level of its test, but it pays a cost that increases in the accuracy. Workers who perform poorly on the test are not offered employment; those who perform poorly on the job are eventually fired (after some delay). Worker quality is not match‐specific; low‐quality workers are less productive with all firms. We show that, in equilibrium, there is an inverse and complementary relation between the level of testing that firms optimally perform and the overall quality of the workers in the matching pool. We consider the properties of a steady‐state, stable equilibrium in such an environment. The complementarity between testing and the composition of the unemployed pool introduces the possibility of multiple equilibria.     

War and peace: Third-party intervention in conflict

This paper develops a simple sequential-move game to characterize the endogeneity of third-party intervention in conflict. We show how a third party's “intervention technology” interacts with the canonical “conflict technologies” of two rival parties in affecting the sub-game perfect Nash equilibrium outcome. From the perspective of deterrence strategy, we find that it is more costly for a third party to support an ally to deter a challenger from attacking (i.e., to maintain peace or acquiescence), as compared to the alternative case when the third party supports the ally to gain a disputed territory by attacking (i.e., to create war), ceteris paribus. However, an optimally intervening third party can be either “peace-making”, “peace-breaking”, or neither depending on the characteristics of the conflict and the stakes the third party holds with each of the rival parties.     

Breeding and raiding: A theory of strategic production of skills

Some of the skills that firms require are obtained only through on-the-job-training. This paper concentrates on the strategic production of skills within the firm. Firms obtain high-quality workers either by training their own (breeding) or by using the open market to bid away workers trained by other firms (raiding). Even when all firms have access to the same technology of production, training, and breeding, it will typically be the case that both breeding and raiding will be pursued, with equal profitability, in equilibrium. Thus, we explain raiding behavior as part of an equilibrium theory. This paper also studies the effect of the decision to train workers on the optimal firm size and the distribution of income.     

Workers with Disabilities: Exploring the Hiring Intentions of Nonprofit and For-profit Employers

Using the Theory of Planned Behavior as a conceptual framework, focus groups were held with nonprofit and for-profit employers in order to examine behavioral intentions to hire workers with disabilities. Content analysis revealed the following main themes: (1) For-profit hiring strategies were driven by a mission to sell a product or service; (2) Nonprofit hiring strategies were driven by a mission to serve the community; (3) Forprofit hiring and nonprofit hiring were impacted by the economy; (4) Although driven to have diverse workforces, the number of workers with disabilities was largely unknown; and (5) Employer attitudes mattered and impacted job opportunities for people with disabilities. Implications of this qualitative study highlight the utility of the Theory of Planned Behavior and the role that nonprofit managers and leaders may play in improving employment opportunities for individuals with disabilities.     

Uniform confidence bands for functions estimated nonparametrically with instrumental variables

This paper is concerned with developing uniform confidence bands for functions estimated nonparametrically with instrumental variables. We show that a sieve nonparametric instrumental variables estimator is pointwise asymptotically normally distributed. The asymptotic normality result holds in both mildly and severely ill-posed cases. We present methods to obtain a uniform confidence band and show that the bootstrap can be used to obtain the required critical values. Monte Carlo experiments illustrate the finite-sample performance of the uniform confidence band.