A further important issue facing policymakers in developing countries is whether the current number of facilities should be increased or reduced to cope with the existing workload. This depends on how far economies of scale have been exploited-the conventional wisdom being that unexploited economies of scale imply too many producers. In the multiproduct case (where, for example, hospitals are treating inpatient and outpatient cases), one needs to work with the concept of _ray_ economies of scale, which show how costs change when all outputs are increased in the same proportion. Ray economies of scale depend in part on product-specific economies of scale, and in part on economies of scope. Two of the studies reviewed by Wagstaff and Barnum (1992) prejudge the issue of economies of scale. Dor's (1987) specification, for example, implicitly assumes that the product-specific economies-of-scale index is equal to one for all outputs. Given this, the link between ray economies of scale, economies of scope and product-specific economies of scale, and that the specification in effect rules out economies of scope, it follows that the specification forces ray diseconomies of scale. Bitran-Dicowsky and Dunlop (1993) find slight product-specific diseconomies of scale but find ray economies of scale. The implication is that these stem from the economies of scope noted above. Wouters (1993) also finds ray economies of scale but in contrast to Bitran-Dicowsky and Dunlop finds product-specific economies.

# V. CGIindl olln$

This paper has reviewed facility survey approaches. From the foregoing discussion it is clear that "facility surveys" have varied extensively-in terms of motivation, type of data collected, methods of data collection, and use of the data. Some surveys have focused specifically on the health care provider, which receives resources, delivers services to the community, interacts with other providers, and reports on activities and outputs. In other surveys, the primary object of analysis has been the household, which is the ultimate beneficiary of the services, who may make payments to the provider, and who may have a role in holding the provider accountable. Finally, some surveys have sought to shed light on the administrative and logistical system "upstream" from the service delivery unit. This system is responsible for channeling resources to the service delivery unit, and provides the institutional framework for regulation, supervision, provider payment, etc.

What are the lessons that emerge from the experiences to date, and what should be the empirical agenda for the future? One point to emerge is that since many of the issues of interest concern the interaction between different units in the system, it is necessary to look beyond a single part of the system. Indeed, this is precisely the rationale behind the first community and facility surveys implemented in conjunction with the DHS and LSMS surveys. However, while these surveys have taught us a lot about how health behaviors and outcomes relate to service availability and provider characteristics, many questions remain unanswered. This is true not only for the relationship between households, the community, and the provider, but also in respect of the strategic interaction between different providers, and between the administrative and logistical system and providers.

Another point to emerge is that there are difficult methodological issues to resolve concerning the measurement of quality, costs, and outputs. For example, the paper has noted discussed the disparate approaches to measuring health care quality. Is there an emerging best 28