A FTER three decades of intensive government efforts to improve the lot of those at the bottom of the economic heap, the poor are very much with us, and many are both ill-fed and ill-housed. The various measures taken to improve housing conditions among the poor remain to be evaluated; habitability laws are an example. These laws regulate the relationship between landlord and tenant in that they require the former to provide housing in habitable conditions. By subjecting a lease to the doctrine of caveat venditor, rather than caveat emptor as was done before at common law, these laws greatly extend the warranty of habitability. They provide tenants with remedies in the form of repair and deduct, rent withholding and receivership laws, supplemented by laws that prohibit retaliatory eviction. Good summaries of these laws can be found in a number of places (American Law Institute's Restatement (Second) of Property, Landlord and Tenant, 1974 and Hirsch et al., 1975). This paper examines the welfare effects of habitability laws with respect to indigent tenants. This examination, carried out within a demand-supply system, must take into account the intricate and unique aspects of housing as a commodity. Housing is a complex commodity having both stock and flow characteristics. Our interest is mainly in the latter, i.e., the flow of housing services, an area with serious measurement problems. Specifically, in the day-to-day world we find data neither on the quantity of rental housing services nor on their price. Therefore, a hedonic approach to rental housing services, which estimates empirical rent functions, is used. In this manner, the distinctive characteristics of a rental unit are measured and expressed in a single quantity which reflects the market's consensus about their relative importance. The hedonic approach can, thus, provide shadow housing quantities and prices. Used in conjunction with conventional demand and supply variables, plus habitability law variables, demand and supply functions will be estimated. Finally, these functions permit statements about the effects habitability laws are likely to have on the welfare of landlords and tenants. Specifically, to the extent that such laws are enforced and lead to improved repair and maintenance, tenants' well-being will be enhanced and an upward shift of the demand function will occur. On the supply side, habitability laws can affect maintenance and repair decisions, which together with the potential legal costs will also lead to an upward shift of the supply function. The crucial matter is the relative shift of these two functions and the statistical significance of their difference.

ENVIIRONMENTAL health services, especially refuse collection and sewage disposal, though relatively small in terms of outlays compared to other urban government services, have played a major role in the rapid urbanization of society. They have helped to eliminate the frightful dangers to health that can threaten densely populated communities and decimate their populations. Economists who are concerned with planning the provision and financing of urban government services might find the analysis of refuse collection useful from a methodological point of view. Their interests tend to focus on issues of scale economies, break-even points, the cost of differential service levels, the determination of user charges, etc. In addition, projections of service needs and costs occupy their attention. Inquiries into these matters require information on government service demand and cost functions which are unusually difficult to determine because of the economist's inability to find readily quantifiable output units and quality characteristics. However, as will be shown below, refuse collection cost analysis, in this respect, poses less difficulty than any other local government service, except perhaps water supply. In much of the world, refuse collection services are mainly provided by governments, although this need not be the only method.' Indubitably, these services do not constitute pure public goods; only to a limited extent do they fulfill either social or merit wants.2 Or, to put it differently, while pure public goods have very many major indirect or neighborhood effects, in the case of refuse collection such effects are relatively minor. Residential refuse collection (and disposal) service involves the regularly scheduled pickup, collection and disposition by a sanitary agency of solid waste materials resulting from the operation and maintenance of households; its main components are garbage, ashes and rubbish.3 It is useful to distinguish between residential refuse collection on the one hand and industrial refuse collection on the other. The two usually are carried out separately and the latter takes place virtually on a daily basis. Unlike residences, commercial and industrial establishments vary greatly in the amount of refuse they produce, and many large industrial firms provide their own collection and sometimes even disposal service. In the following pages, an ideal residential refuse collection cost model will be presented. Because of data difficulties and the marginal importance of some variables, this model will next be simplified and implemented in relation to a case study. Finally some conclusions are pre-

A GREAT deal of interest in metropolitan area analysis centers around the economic impact of autonomous forces upon any of the area's sectors and upon its totality. Researchers have often felt that even approximate knowledge of the structural relationship of the local economy would greatly facilitate their work. An interindustry flow table has been prepared for the St. Louis area, one of the ten largest metropolitan areas in the United States. From such a table it is but a short step to technical coefficients and the inverse matrix. Furthermore, from these tables income and employment multipliers can be estimated. Both are powerful tools in assessing the impact of final demand changes upon the economic activity of a metropolitan area. Much serious criticism has been leveled in the past against area technical coefficients which are deduced from national ones pertaining to an outdated period. This study undertakes to estimate 1955 coefficients with the help of data obtained directly from a sample of private and public bodies which together constitute the St. Louis metropolitan area economy. Based upon this information some activity and impact projections are attempted.

M ETROPOLITAN areas are growing fast and so are their problems. To make this growth smoother and fiscal problems less burdensome, the consolidation of metropolitan area governments is widely advocated on the premise that it will reduce per capita expenditures of local government services. It is argued that, just as there are economies of scale in manufacturing, average municipal costs and expenditures likewise decline as the size of the local government unit increases. This paper will attempt to develop a theoretical framework for analyzing the question What are the likely expenditure effects of metropolitan growth and consolidation? The deductive answers will then be tested by an empirical analysis of I49 government units in the St. Louis metropolitan area and some Massachusetts cities.

M OST economic cost studies have been concerned primarily with the relation of cost to rate of output. Shortrun costs are usually said to be those associated with variation in the utilization of fixed plant or other facilities, whereas longrun cost encompasses changes in the size and kind of plant. Strictly, then, the distinction is based upon the degree of adaptation of all input factors to rate of output.1 However, cost may vary because of changes in technical knowledge.2 Economists have explicitly excluded all irreversible changes in technology. Most longrun cost theories, for instance, are timeless; one future point in time is selected at which output rate and facilities are permitted to change. That such a cost function, particularly its height, will be affected by improvements in technical knowledge is beyond doubt. It is convenient to clarify the issue of the different cost functions by referring to production functions, which express the net relation between the input of variable productive factors and output during a given production period, under the assumption of a given plant and technical knowledge. From the production function we can derive a static shortrun cost function, which also assumes a given plant and technical knowledge. Longrun cost permits changes in the size and kind of plant, but assumes stability in technical knowledge. Thus, a longrun cost function is related to points on different production functions, each point involving a different plant while using the same technical knowledge. There can be a cost function which permits changes in technical knowledge but not in plant and other facilities. In a sense this is a dynamic cost function. If direct labor is the cost we consider, we shall speak about a (unit) learning or progress function. This expresses the net relation between the amount of direct labor needed to produce one product-unit and the cumulative units produced in a given facility. The progress function thus permits us to estimate the amount of direct labor needed to manufacture the nth unit, from n, the cumulative number of the product-unit. The function is related to a number of points on different production functions involving successive changes in technical knowledge in a given facility. In this study we will analyze data of a large United States machine builder, who has been one of the largest machine tool 3 manufacturers for about three-quarters of a century. Since the end of World War II the company has also manufactured textile and construction machinery. Of its twenty products, seven have been selected for an empirical analysis. They are either new products or new models. Machine i is a new semi-automatic machine tool and machines 2-5 are new automatic machine tools which differ greatly in the functions they perform, weight, labor requirement, etc. Machine 6 is a textile machine and machine 7 is a multipurpose construction machine. Production is carried out in one large plant. During the period under consideration, I946-50, the monthly direct labor force varied from 930 to 3,600 men. The production process is very complicated, calling for high professional skills. It is divided into machining of parts and their assembly. Each month top management decides on a production schedule which instructs the production manager to have ready for shipment by a *The author would like to express his gratitude to the Bureau of Business and Economic Research of the University of California for financial support of this study. 1J. Dean, Managerial Economics (New York, I951), p.

Reviews the book "Foundations of Productivity Analysis: Guides to Economic Theory and Managerial Control," by Bela Gold.

Reviews the book "Approaches to Economic Development," by Norman S. Buchanan and Howard S. Ellis.