Innovative productivity and returns to scale in the pharmaceutical industry

This study shows that firms in the pharmaceutical industry experience decreasing returns to scale in R & D as the level of R & D expenditures rises. The paper presents the results of our study of the innovative output of 16 pharmaceutical firms over a 19 year period. Given the strong correlation between R & D budgets and firm size, our study suggests the wave of mergers in the industry may yield less innovative productivity than managers expect.     

The employee selection interview: A fresh look at an old problem

This article takes a fresh look at employee selection interviews as they are practiced in most organizations. Interviewers' selection decisions are demonstrated to be idiosyncratic and it is concluded that variation in interviewers' decision processes jeopardizes organizational effectiveness. Practical recommendations for improving employment interviews are offered. © 1996 by John Wiley & Sons, Inc.     

Amenities and Fringe Benefits: Omitted Variable Bias

ABSTRACT If labor is fairly mobile, as it is in the United States, one would expect that households would move from less desirable areas toward more desirable areas until all areas are equally desirable. The way that areas become equally desirable is through the impact of movers on wages and rents (and possibly "endogenous" disamenities, such as congestion or pollution). That is, as people move to desirable areas, they will increase the demand for land (raising rents) and increase the supply of labor (lowering wages); in equilibrium, the wage and rent "compensation" for the niceness of an area reveals, in dollar terms, just how nice the area is. Blomquist, Berger, and Hoehn 1988 demonstrated the empirical importance of such amenity compensation in estimates of the "quality-of-life" in urban areas. However, those authors were unable to include fringe benefits, which are about 40 percent of explicit wage payments, in their wage compensation. This matters greatly as amenities are seen here to be even more important than previously thought and the regional implications are pronounced, with the West and Southeast looking "better" when fringe benefits are included and the East North Central and Northeast looking substantially "worse."     

Overlapping operations in material requirements planning

Material requirements planning (MRP) is a planning and information system that has widespread application in discrete-parts manufacturing. The purpose of this article is to introduce ideas that can improve the flow of material through complex manufacturing systems operating under MRP, and that can increase the applicability of MRP within diverse manufacturing environments.MRP models the flow of material by assuming that items flow from work station to work station in the same batches that are used in production. That is, once work starts on a batch of a certain item at a certain work station, the entire batch will be produced before any part of the batch will be transported to the next work station on its routing plan. Clearly, efficiency can be increased if some parallelism can be introduced. The form of parallelism investigated here is overlapping operations.Overlapping operations occurs when the transportation of partial batches to a downstream work station is allowed while work proceeds to complete the batch at the upstream work station. The potential efficiencies to be gained are the following:

• Reduced work-in-process inventory

• Reduced floor space requirements

• Reduced size of transfer vehicles

Additional costs may accrue through additional cost of transportation of partial batches and through additional costs of control.Some MRP software vendors provide the data processing capability for overlapping operations. However, the user is given little or no guidance on overlapping percentages or amounts. It is our intent to provide a simple, robust technique to MRP users who would like to overlap operations and gain some or all of the above efficiencies.An optimal lot-sizing technique is derived by considering a generic two work station segment of a manufacturing system. Under the assumptions of constant demand and identical production rates, a cost function that considers setup costs, inventory holding costs and transportation costs is derived. This cost function is minimized subject to the constraint that the production batch is an integer multiple of the transfer batch. We solve for the optimal production batch, the optimal transfer batch, and the integer number relating them. Solutions are obtained as closed form, easy to-evaluate formulas.By introducing more parallelism, overlapping operations can reduce lead time. However, this will not happen without modification of MRP logic to accommodate such reduced lead time. We derive a formula that shows how a significant lead time compression can easily be obtained and implemented in MRP.We consider an example to illustrate the application of the technique on typical data from the electronics industry. The outcome showed a cost savings of approximately 22.5% over the standard MRP approach.Overlapping operations allows the applicability of MRP to an increasing number of situations that are not modeled faithfully by conventional MRP logic. Three such situations that occur often are the following:

• Limited size of transfer vehicles dictate that several transfers should be planned.

• Lead time requirements prohibit nonoverlapped operations.

Our analysis suggests how to accommodate these difficult practical situations into MRP.Overlapping operations in material requirements planning provides an enhancement that allows wider applicability, shortened lead times, and lower total costs. It may be applied selectively to any two work stations where it is deemed appropriate. Due to the structure of the cost function, it is possible to make the transfer lot-sizing decisions independent of the production lot-sizing decisions. Therefore, significant improvements can be made through overlapping with minimum disruption to the existing MRP system machinery. It is our conviction that overlapping operations is an important concept that can and will impact MRP. We suggest the approach presented here as a systematic way to implement overlapping.     

The Educational Choice Anomaly for Principles Students: Using Ordinary Supply and Demand Rather than Indifference Curves

The surprise value of many economic observations makes the economics discipline quite interesting for many students. One such anomaly is that providing “free” education in an effort to reduce the number of dropouts can often result in a lower level of educational quality purchased. This result is easy to show with indifference curves, but many instructors of introductory courses do not introduce this analytical technique. As a consequence, a result that many students find quite interesting is seldom presented. The authors show that it is easy to clarify the educational choice anomaly with ordinary supply and demand curves. Moreover, the exercise of doing so provides students with a greater understanding of benefit/cost analysis as well as consumer and producer surplus.     

Long‐term effects of alcohol warning labels: Findings from a comparison of the United States and Ontario,Canada

Since 1989 the U.S. federal government has required warnings on alcohol containers. Findings are presented from telephone surveys conducted between 1990 and 1994 in the U.S. and Ontario, Canada, the no‐treatment reference site. In the U.S., penetration peaked in 1993–94, with 43% of the lifetime drinkers reporting label awareness. Label exposure was weaker (<20%) for all years in the reference site. The proportion reporting conversations about drinking during pregnancy was higher among label seers in both sites. Those seeing labels in the U.S. were more likely to engage in conversations about drinking and driving than those not seeing. Reports of limiting drinking for health reasons showed a positive association with label exposure increasing with time. In the U.S. only, across all years, controlling for age, gender, education, and alcohol consumption, label seers were more likely to drive after drinking too much, but also to say they had deliberately not driven after drinking during the last year. Findings from this quasi‐experiment cannot establish causal relationships, but the pattern of results, though mixed, suggests modest effects on conversations and several precautionary behaviors related to risks of drinking. The label's effects may partially offset an overall trend toward lower public concern about health risks of alcohol. Results are interpreted as consistent with Congressional intent to remind people of certain hazards of drinking, especially during pregnancy or before driving vehicles. © 1999 John Wiley & Sons, Inc.     

Incorporating inventories into supply and demand analysis

Conclusion In the microeconomic portions of principles and intermediate macroeconomics, supply and demand analysis is presented as the truth. However, the simple Keynesian macroeconomic model virtually ignores market clearing, while the standard microeconomic model of supply and demand assumes perfect market clearing. Since hidden assumptions are a major source of confusion and misunderstanding between economists and the general public, students should be exposed to stock-flow analysis at the intermediate level as a separate or integrated chapter on supply and demand.