Evidence of Large-Scale Social Interactions in Mammography in the United States

This paper examines the extent of social interactions in an individual’s decision to undergo mammography. Using Behavioral Risk Factors Surveillance System surveys from 1993 to 2016, the effect of other female screening behavior on an individual’s decision to have a routine breast cancer screening was measured by calculating the size of a so called “social multiplier” in mammography. A vector of social multipliers was estimated in the use of mammograms in the past 1–2 years by taking the ratio of group-level effects of exogenous explanatory variables to individual-level effects of the same variables. Peer groups were defined as same-aged women living in the same state. Three age groups of women were considered: 40–49, 50–74, and 75 and older. Several econometric approaches were used to analyze the effect of social interactions on mammography use, including ordinary least squares, fixed effects, and split-sample instrumental variable. For all women, evidence was found of social interactions associated with individual’s education, employment, and poor health. In addition, number of age-group-specific social multipliers was found. The strongest evidence of spillover in mammography was found for women ages 75 and older. Policy makers should be aware that, in the presence of a social multiplier, the value of any type of screening intervention is higher than the one that would be measured at the individual-level.

     

Time Series Concepts for Conditional Distributions*

The paper asks the question – as time series analysis moves from consideration of conditional mean values and variances to unconditional distributions, do some of the familiar concepts devised for the first two moments continue to be helpful in the more general area? Most seem to generalize fairly easy, such as the concepts of breaks, seasonality, trends and regime switching. Forecasting is more difficult, as forecasts become distributions, as do forecast errors. Persistence can be defined and also common factors by using the idea of a copula. Aggregation is more difficult but causality and controllability can be defined. The study of the time series of quantiles becomes more relevant.     

Updating the Determinants of Firm Performance: Estimation using the 1998 UK Workplace Employee Relations Survey

We examine the determinants of establishment performance in the UK, using cross‐sectional data from the 1998 Workplace Employee Relations Survey to replicate research by Fernie and Metcalf (1995) who used data from the 1990 Workplace Employee Relations Survey; specifically, we test whether employee representation, contingent pay and efforts to boost employee participation affect a set of economic and industrial relations outcome indicators in the manner they suggest. We also re‐estimate the influential WERS90‐based study of Machin and Stewart (1996) on the links between union status and financial performance. In both cases we report very different results.     

Reviews

'New technology a health and safety report'

APEX, London and Home Counties Area Sub-Committee; New Technology; a Health and Safety Report, February 1985. (Available from APEX, 3 Parkview Road, Welling, Kent, 0A16 1SZ, tel. 01-303 3407/8.)     

Combining Expert Systems and Hypertext: Opportunities and Obstacles

Hypertext discussions are occurring more frequently at expert systems conferences. Hypertext is not an expert system language or expert system shell, but instead it is simultaneously a method of storing and retrieving data. The growing interest in hypertext in the expert system domain is because the combination of hypertext capabilities and expert systems creates a compelling synergistic relationship (Oren, 1987). During a panel discussion at the Second International Symposium on Expert Systems in Business, Finance and Accounting, Bill Swartout compared traditional expert systems to hypertext by saying that the knowledge base (e.g. the production rules) of an expert system can be thought of as formal knowledge and hypertext can be thought of as informal knowledge. This article will demonstrate how this informal knowledge can add power to traditional expert systems by increasing the flexibility of the explanation facilities and thereby the appeal of the system to a broader range of users. The article also will discuss how expert systems can improve the functionality of hypertext systems by adding intelligence to traditional hypertext systems. This article is divided into three sections. The first describes basic hypertext concepts. The second section shows how hypertext can enhance expert systems and, conversely, how expert systems can enhance hypertext systems. The final section discusses some potential problems and concerns that must be considered when designing a hypertext system.     

Risk and Capital Structure in the Regulated Firm

This paper studies the role of capital structure in a regulated firm. We show that it affects the prices set by the regulator, the expected price being lower the higher the proportion of debt finance. However, when debt is increased beyond a certain level, the benefit of lower expected prices is offset by their increased variability. We also study the socially preferred capital structure. This is such that consumers carry some risk, in the form of higher prices in adverse economic conditions.     

Agency Structure and Firm Culture: OSHA, EPA, and the Steel Industry

We compare models of Occupational Safety and Health Administration(OSHA) and Environmental Protection Agency (EPA) enforcementand compliance for steel plants during the 1980s. We find thatOSHA and EPA respond similarly to plant-level compliance andmeasures of hazardousness, but differently to firm-level complianceand risks of plant closing, and we relate the differences tothe agencies' differing organizational structures. Plant-levelcompliance is affected by enforcement pressure, compliance costs,and the firm's overall compliance behavior in similar ways forthe two regulatory areas, but environmental compliance was alsosensitive to plant size and risk of closing. Finally, we findthat the likelihood that a plant was in compliance with oneagency seemed at most weakly related to whether it was in compliancewith the other, but that plants likely to receive enforcementattention from one agency were also more likely to receive enforcementattention from the other agency.