PubMed Health⌕ Search

Biomedical subjects

D Wholey

Publications and source records attributed to D Wholey.

10 recordsLinked to original sources
PubMed2001

Do HMOs have monopsony power?

OBJECTIVE: To determine whether health maintenance organizations (HMOs) have monopsony power in the markets for ambulatory care and inpatient hospital services. DATA SOURCES: A pooled time-series of data on all HMOs operating in the United States from 1985 through 1997. Information reported to InterStudy on HMO market areas and enrollment is linked to financial data reported to state regulators and county characteristics from the Area Resource File (ARF). STUDY DESIGN: We use a two-stage design to test for the existence of monopsony power. First, we estimate regression equations for the prices paid by HMOs for ambulatory visits and inpatient hospital days. The key independent variable is a measure of the importance of an individual HMO as a buyer of ambulatory care or hospital services. Second, we estimate regressions for the utilization of ambulatory visits and inpatient hospital days per HMO enrollee, as a function of HMO buying power and other variables. PRINCIPAL FINDINGS: Increased HMO buying power is associated with lower price and higher utilization of hospital services. Buying power is not related to ambulatory visit price or utilization per member. CONCLUSIONS: Our findings are not consistent with the monopsony hypothesis. They suggest that managed care organizations have contributed to a welfare-increasing breakup of hospital monopoly power. The role of HMOs as buyers of ambulatory services is more complex. We discuss possible reasons why buying power may not affect price or utilization of ambulatory visits.

Ambulatory Care↗
PubMed2000

Choosing Work Group Members: Balancing Similarity, Competence, and Familiarity.

This study explores one of the contributors to group composition-the basis on which people choose others with whom they want to work. We use a combined model to explore individual attributes, relational attributes, and previous structural ties as determinants of work partner choice. Four years of data from participants in 33 small project groups were collected, some of which reflects individual participant characteristics and some of which is social network data measuring the previous relationship between two participants. Our results suggest that when selecting future group members people are biased toward others of the same race, others who have a reputation for being competent and hard working, and others with whom they have developed strong working relationships in the past. These results suggest that people strive for predictability when choosing future work group members. Copyright 2000 Academic Press.

Journal Article↗
PubMed1998

Do Medicare HMOs cost shift?

We tested the hypothesis that health maintenance organizations (HMOs) increase their commercial premiums when Medicare pays less. Such a linkage would be taken as evidence of "cost shifting." Other studies have tested the cost-shifting hypothesis among health care providers, but this is the first to examine the HMO industry. Our data consisted of annual observations on all HMOs that operated in the United States between 1990 and 1995 and had a Medicare risk contract. A comparison group of HMOs that had no Medicare contract during that period also was analyzed. The main finding from this study is that HMOs have not shifted costs from Medicare to commercial premiums. This results supports the skeptical consensus that is developing toward the cost-shifting hypothesis. Additional findings include the negative effects of competition and for-profit status on HMOs' commercial premiums.

Contract Services↗
PubMed1996

Scale and scope economies among health maintenance organizations.

We examine scale and scope economics among Group and IPA Health Maintenance Organizations (HMOs) over the period 1988 to 1991 using a national sample of HMOs. We allow for the multiproduct nature of HMO production by estimating the cost of producing a member month of non-Medicare and Medicare coverage, and we examine the effect of HMO market structure on costs. We find that HMOs benefit from scale economies. There are scope diseconomies associated with providing both non-Medicare and Medicare products. Group HMOs in more competitive markets have lower costs but IPA costs are not affected by competition.

Economic Competition↗
PubMed1996

Effect of mergers on health maintenance organization premiums.

This study estimated the effect of mergers on health maintenance organization (HMO) premiums, using data on all operational non-Medicaid HMOs in the United States from 1985 to 1993. Two critical issues were examined: whether HMO mergers increase or decrease premiums; and whether the effects of mergers differ according to the degree of competition among HMOs in local markets. The only significant merger effect was found in the most competitive markets, where premiums increased, but only for 1 year after the merger. Our research does not support the argument that consolidation of HMOs in local markets will benefit consumers through lower premiums.

Capitation Fee↗
PubMed1996

Economic and organizational determinants of HMO mergers and failures.

This study analyzed data from all operational health maintenance organizations (HMOs) in the United States from 1986 through 1993. Eighty HMOs disappeared through mergers and 149 failed over that period. We estimated a multinomial logit model to predict whether an HMO would merge and survive, merge and disappear, or fail, relative to the probability of no event. We found that enrollment and profitability play a critical role in explaining HMO mergers and failures: large and profitable HMOs were more likely to merge and survive, but less likely to merge and disappear or fail. These results explain why HMO merger and failure rates fell after 1988, as most surviving HMOs became larger and more profitable. Among several market-area variables in the model, state anti-takeover regulations had a negative impact on mergers. Mergers were more likely in markets with more competing HMOs, but the overall market penetration of HMOs had no effect on mergers. This result may have important implications for the current debate over the future of the competitive health care strategy. If public policy successfully stimulates the development of large numbers of new HMOs, another wave of mergers and failures is likely to occur. But it appears that growth in overall HMO penetration will not lead inevitably to increased market concentration.

Bankruptcy↗
PubMed1995

The effect of market structure on HMO premiums.

We examine the effects of HMO market structure on HMO premiums from 1988 to 1991. More competition, measured by the number of HMOs in the market area, reduces HMO premiums. Although this effect does not appear for IPAs before the highest level of competition is reached, it appears throughout the competitive range for Group HMOs. More market penetration, measured by the percent of the market area population enrolled in HMOs, reduces premiums for IPAs. Since the goal of managed competition is to reduce health care costs by creating competition among managed health care plans, our results offer encouragement for managed competition advocates.

Capitation Fee↗
PubMed1993

Creating the market under managed competition: getting there will not be half the fun.

To develop a framework for managed competition, implementers of health care reform will need to encourage the development of a large number of new AHPs. If experience with the rapid growth in HMOs that occurred in the late 1980s can serve as a guide, it would be expected that many new IPAs will form and that their development will occur at different rates in different communities, depending in part on the supply of medical resources and population demographics. There is evidence from past studies that new IPA entrants can stimulate the price competition desired by health care reformers. Lower bid prices were submitted by plans in the AHCCCS program in markets where new IPAs were competitors. IPAs also can fail, however, particularly at low enrollment levels. Implementers need to be concerned about the political and operational consequences of AHP failures during the early stages of health reform. If managed competition is to contain costs, implementers will need to develop effective policies to stimulate AHP entry, to oversee the performance of new AHPs during initial periods of low enrollment, and to protect consumers from any adverse consequences of AHP failures. It is possible that a large number of failures could occur among newly formed AHPs and that such failures could undermine the confidence of the public in managed competition. This would probably lead to calls for the replacement of managed competition with a more centrally managed and closely regulated health care system.

Competitive Medical Plans↗