Reconceptualizing and expanding the positive feedback network effects model: A case study

During the 1980s, economists developed the concept of positive network effects and switching costs as the key dynamics of de facto standards competition. They concluded that a positive feedback loop usually “tips” a market to the standard with the most users and complementary assets. While recent scholars have acknowledged that not all markets tip, and suggested some possible limitations on this phenomena, these limitations have not been integrated systematically into a model for competition in these industries. Using examples drawn from the standards contests of the past 20 years, this case study develops an integrated model for competition in these industries.     

Online scheduling with a buffer on related machines

Online scheduling with a buffer is a semi-online problem which is strongly related to the basic online scheduling problem. Jobs arrive one by one and are to be assigned to parallel machines. A buffer of a fixed capacity K is available for storing at most K input jobs. An arriving job must be either assigned to a machine immediately upon arrival, or it can be stored in the buffer for unlimited time. A stored job which is removed from the buffer (possibly, in order to allocate a space in the buffer for a new job) must be assigned immediately as well. We study the case of two uniformly related machines of speed ratio s≥1, with the goal of makespan minimization.     

Interpreting MSHA Citations Through the Lens of Occupational Health and Safety Management Systems: Investigating Their Impact on Mine Injuries and Illnesses 2003–2010

Since the late 1980s, the U.S. Department of Labor has considered regulating a systems approach to occupational health and safety management. Recently, a health and safety management systems (HSMS) standard has returned to the regulatory agenda of both the Occupational Safety and Health Administration (OSHA) and the Mine Safety and Health Administration (MSHA). Because a mandated standard has implications for both industry and regulating bodies alike, it is imperative to gain a greater understanding of the potential effects that an HSMS regulatory approach can have on establishment‐level injuries and illnesses. Through the lens of MSHA's regulatory framework, we first explore how current enforcement activities align with HSMS elements. Using MSHA data for the years 2003–2010, we then analyze the relationship between various types of enforcement activities (e.g., total number of citations, total penalty amount, and HSMS‐aligned citations) and mine reportable injuries. Our findings show that the reduction in mine reportable injuries predicted by increases in MSHA enforcement ranges from negligible to 18%. The results suggest that the type and focus of the enforcement activity may be more important for accident reduction than the total number of citations issued and the associated penalty amount.     

Popular Hazards and Policy Rhetoric

Popular hazards are common activities that involve some risks of harm, such as driving a car, possessing or shooting a gun, drinking alcohol, or smoking marijuana. In each of these cases, many millions of Americans engage in the activity, but only a small fraction of them harm themselves or other people. Because the activity is so common, the number harmed may be substantial, although more serious harms tend to be much more infrequent than less serious harms. Social policy debates almost always focus on some particular popular hazard, yet we can see rhetorical similarities—parallel arguments—in how advocates frame what are understood to be very different social issues. Thus, discourse about legalizing recreational marijuana use tends to invoke claims that are quite similar to those opposing further gun control. The category of popular hazards allows us to recognize parallels in policy debates about seemingly unrelated social issues. Focusing on the underlying policy issue—balancing popularity and hazardousness—encourages considering alternative ways to construct social policies.     

The self‐concept of the delinquent female 1

Interviewing: Its Principles and Methods, Annette Garrett, Second Edition, FSAA, New York, 1972

The Experience of Psychotherapy: A Practitioner's Manual, Herbert S. Strean, Metuchen, New Jersey: The Scarecrow Press Inc., 1973.     

The effect of earthworms on roadway-derived Zn deposited as a surface layer in storm water retention basin soils

Increased urban development, including an increase in impervious surfaces has the potential to alter the biogeochemistry of surface systems due to storm water runoff contaminated with potentially toxic trace metals (e.g. Zn, Cu and Pb). A major source for urban metals is dust that accumulates on roadways. This roadway dust is derived from vehicle wear sources and tends to be enriched in trace metals such as Pb, Zn, Cu, Cd, Ni and Cr. This continuous source is then being transported via storm water runoff to receiving systems, such as storm water retention systems, which become important focusing environments for trace metal deposition. The fate of these roadway derived metals and their bioavailability once deposited in these urban ecosystems is not well understood. In this investigation we tested the hypothesis that the distribution and form of surface deposited roadway-derived Zn is a function of earthworm processes and is species dependent. The results of this investigation indicate that roadway dust derived Zn deposited as a surface layer on urban soils is readily removed from the surface in less than 30 days whether earthworms are present or not. However, after 90 days, the presence of earthworms and the life habit of the earthworm species present was found to have a significant impact on the physical and chemical cycling of roadway derived trace metals in storm water retention basin soils.     

Robust Confidence Regions for Incomplete Models

Call an economic model incomplete if it does not generate a probabilistic prediction even given knowledge of all parameter values. We propose a method of inference about unknown parameters for such models that is robust to heterogeneity and dependence of unknown form. The key is a Central Limit Theorem for belief functions; robust confidence regions are then constructed in a fashion paralleling the classical approach. Monte Carlo simulations support tractability of the method and demonstrate its enhanced robustness relative to existing methods.     

Gifts, Cash, and Stigma

Each year individuals in the United States transfer between $50 and $72 billion in resources in the form of noncash holiday gifts, despite the fact that holiday gift recipients apparently value their noncash gifts at about 10% less than the prices paid by the givers. We document that cash giving is more likely from givers who tend to give unwanted gifts, indicating that givers are concerned with the utility of their recipients. The rarity of cash gifts can be rationalized by a stigma of cash giving that we are able to parameterize and estimate using a simple structural model.