Survival strategies in the era of managed care

The era of managed care has forced an unprecedented restructuring of the health care environment. As hospitals downsize in response, materiel managers should consider adopting strategies that may help ensure their survival, including innovative approaches to supply management and the development of individual responses that will best position them to succeed in this new reality.     

Trading cost expectations: Evidence from S&P 500 index replacement stock announcements

This paper tests the effect on stock value of an expected change in future trading costs. The capitalized value of a reduction in trading costs is hypothesized to increase the stock value, a trading cost effect. Improved liquidity reduces trading costs. Inclusion as an S&P 500 Index replacement stock is an event hypothesized to increase liquidity. We use 114 observations between January 1, 1983 and October 12, 1989 of stocks added to the Index as replacements for stocks removed. The abnormal return of each stock is regressed against the ratio of the bidask spread to the price of the stock, the change in trading volume of the stock, and the open interest in the Index futures contracts at the close of the month prior to the replacement announcement. We find that the positive abnormal returns for replacement stocks are related to increased daily trading volume after inclusion in the Index. Further, the trading cost effect is proportional to percentage bid-ask spreads prior to inclusion. The trading cost effect increases as trading in derivatives of the Index increases. The volume and stock price changes after replacement are not transitory, indicating an improvement in liquidity. Three alternate hypotheses suggested in prior research to explain the abnormal returns for replacement stocks are tested. Testing each of the three models previously considered: price pressure, inelastic demand curves, and information, we find that none can be accepted with statistical confidence. The abnormal returns of Index replacement stocks are consistent with rational pricing of an anticipated reduction in future transaction costs. This anticipated reduction is capitalized in the value of the stock at the time of the replacement announcement. These results are consistent with a trading cost effect.     

ENVIRONMENTAL FINANCE: VALUE AND RISK IN AN AGE OF ECOLOGY

Environmental issues are restructuring markets and redirecting capital flows throughout the world. An outline is provided of concerns facing the development of an environmentally responsible or ‘environmental finance’ perspective. It reviews the major ways in which organizations are responding to environmental threats and opportunities in the three major branches of finance — corporate finance, investments and financial institutions — highlighting in particular novel programs and initiatives. In the past, financial concerns have exacerbated the degradation of the natural environment; in the future, they probably hold the key to their preservation.     

Analyzing the volume and nature of emergency medical calls during severe weather events using regression methodologies

An effective emergency medical service (EMS) response to emergency medical calls during extreme weather events is a critical public service. Nearly all models for allocating EMS resources focus on normal operating conditions. However, public health risks become even more critical during extreme weather events, and hence, EMS systems must consider additional needs that arise during weather events to effectively respond to and treat patients. This paper seeks to characterize how the volume and nature of EMS calls are affected during extreme weather events with a particular focus on emergency preparedness. In contrast to other studies on disaster relief, where the focus is on delivery of temporary commodities, we focus on the delivery of routine emergency services during blizzards and hurricane evacuations. The dependence of emergency service quality on weather conditions is explored through a case study using real-world data from Hanover County, Virginia. The results suggest that whether it is snowing is significant in nearly all of the regression models. Variables associated with increased highway congestion, which become important during hurricane evacuations, are positively correlated with an increased call volume and the likelihood of high-risk calls. The analysis can aid public safety leaders in preparing for extreme weather events.     

What is a strategic acquisition? Decision modeling in support of foreclosed housing redevelopment

This paper describes and develops a model for calculating location-based strategic values of foreclosed properties considered for acquisition and redevelopment by community development corporations (CDCs). A property’s strategic value refers to its proximity to site-specific neighborhood amenities and disamenities (e.g. schools, public transit, distressed properties), given the relative importance of that proximity to CDC organizational and community objectives. We operationalize the concept of strategic value, and apply this concept to a salient public sector decision problem. Using data and value assessments from a CDC engaged in foreclosed housing redevelopment, we compute measures of strategic value for a set of acquisition candidates. We show that strategic values can differ in systematic ways depending on the types of amenities and disamenities identified as relevant for CDC acquisition decisions, the relative importance assigned to those amenities and disamenities, and the utility maximization objectives of the CDC. We conclude by proposing a multi-criteria decision model for foreclosed housing acquisition and redevelopment which incorporates a theory of residential housing impacts for which strategic value measures are a special case.     

A true simulation study of three estimators at equal protection of respondents in randomized response sampling

In this study, three different estimators for estimating the proportion of a sensitive attribute in survey sampling are compared at equal protection of the respondents. The three estimators considered are due to Odumade and Singh (2009, Comm. Statist. Theory Methods) , Singh and Sedory (2011, Sociological Methods and Research) and a new estimator obtained by minimizing a chi‐squared distance. A SAS Macro is developed to compare these three estimators using a simulation study at equal protection of the respondents. A set of data from a real face‐to‐face interview was collected using two decks of cards and has been analyzed. The results are discussed.     

R-estimation of the parameters of a multiple regression model with measurement errors

We consider the theory of R-estimation of the regression parameters of a multiple regression models with measurement errors. Using the standard linear rank statistics, R-estimators are defined and their asymptotic properties are studied as robust alternatives to the least squares estimator. This paper fills the gap of the rank theory for the estimation of regression parameters with measurement error models. Some simulation results are presented to show the effectiveness of the R-estimators.     

Fuzzy measurement of income inequality: Some possibility results on the fuzzification of the lorenz ordering

Summary This paper starts from the premise that the concept of income inequality is ill-defined, and hence, it studies the measurement of income inequality from a fuzzy set theoretical point of view. It is argued that the standard (fuzzy) transitivity concepts are not compatible with fuzzy inequality orderings which respect Lorenz ordering. For instance, we show that there does not exist a max-min transitive fuzzy relation on a given income distribution space which ranks distributions unambiguously according to the Lorenz criterion whenever they can actually be ranked by it. Weakening the imposed transitivity concept, it is possible to escape from the noted impossibility theorems. We introduce some alternative transitivity concepts for fuzzy relations, and subsequently, construct a class of fuzzy orderings which preserve Lorenz ordering and satisfy these alternative transitivities. It is also shown that fuzzy measurement can be used to construct confidence intervals for the crisp conclusions of inequality indices.I wish to thank Ashish Banerjee, Kaushik Basu, Larry Blume, Gary Fields, Semih Koray, Tapan Mitra, Antony Shorrocks, Sinan Unur and two anonymous referees of this journal for insighthul comments and suggestions. I am also grateful to the participants of the 1993 Midwest Mathematical Economics Conference held in University of Wisconsin at Madison and the 2nd International Meeting of the Society for Social Choice and Welfare held in University of Rochester.     

How to control a chaotic economy?

An economic system which exhibits chaotic behaviour has been stabilized on various periodic orbits by use of the Ott-Grebogi-Yorke method. This procedure has been recently applied to controlling chaotic phenomena in physical, chemical and biological systems. We adopt this method successfully for Feichtinger's generic model of two competing firms with asymmetrical investment strategies. We show that the application of this control method to the particular economic process considered brings a substantial advantage: one can easily switch from a chaotic trajectory to a regular periodic orbit and simultaneously improve the system's economic properties. Numerical simulations are presented in order to illustrate the effectiveness of the whole procedure.The work was supported by the Alexander von Humboldt-Stiftung and by the Polish National Council (KBN) Grant No 2 P302 038 04.