Ching-to Albert Ma

Learn More
This paper considers a public provider's strategic use of rationing in a market served by both public and private providers. Such a 'mixed' market structure is common in many industries such as health care, telecommunication, postal service, and public utilities. The technology in the private sector exhibits increasing returns: each firm can expend 'effort'(More)
A model of vertical integration is studied. Upstream firms sell differentiated inputs; downstream firms bundle them to make final products. Downstream products are sold as option contracts, which allow consumers to choose from a set of commodities at predetermined prices. The model is illustrated by examples in telecommunication and health markets.(More)
for helpful conversations, and seminar participants at many universities and conferences for their comments. Editor Joe Harrington and two referees gave us very valuable comments and suggestions. Abstract We analyze a model where Þrms compete with prices and qualities in markets consisting of consumers with heterogenous preferences and cost characteristics.(More)
BACKGROUND In the health care market managed care has become the latest innovation for the delivery of services. For efficient implementation, the managed care organization relies on accurate information. So clinicians are often asked to report on patients before referrals are approved, treatments authorized, or insurance claims processed. What are(More)
We study how market conditions influence referrals of patients by general practitioners (GPs). We set up a model of GP referral for the Norwegian health care system, where a GP receives capitation payment based on the number of patients in his practice, as well as fee-for-service reimbursements. A GP may accept new patients or close the practice to new(More)
This study looks at the effect of performance-based contracting (PBC) on administrative information misreports in substance abuse treatment in Maine. For about 700 alcohol abuse treatment episodes in the period 1990-1995, we constructed clinician report gaming indicators from two data sets: the Maine Addiction Treatment System (MATS) and medical record(More)