FITTING FINITE MIXTURE MODELS IN A REGRESSION CONTEXT

Suppose data are collected in a three-mode fashion (individuals x items X attributes), and it is sought to cluster the individuals into groups on the basis of lineat relations between scores on the attributes for each item and auxiliary measurements made on the same items. A mixture model is pro posed and the EM algorithm is used to fit it to the data by simultaneously estimating the group parameters and allocating individuals to groups. The method is illustrated by a simulation study and a real example in which consumers are clustered on the basis of product scores that are related to a sensory laboratory measurement.     

Further discussion of the quantitative limitation of population growth and planned adjustment]

The problem of the quantitative limitation of population growth is related to the development of economic and social productivity. Under a Socialist system, the reproduction of people themselves may follow a projected plan, in order that population growth may match economic growth, the quality of the population may be promoted, and sufficient employment will be possible for the entire labor force. The problem of the quantitative limitation of population growth, however, still exists. In the early stage of social development under Socialism, a quantitative limitation of population growth and planned adjustment were necessary in order to provide enough basic needs for daily livelihood and employment. In the later stage of social development, a quantitative limitation of the population growth and planned adjustment are still needed for the purpose of promoting population quality and ensuring the entire development of the people. Under a socialist system, excessive labor productivity will not produce pressure on the population; instead, it will provide new content for the planned adjustment of people's production and reproduction. From here, the capability of dealing with the problem of the newly increased population will be strengthened, and also the capability of working out a planned adjustment between the two productions will be enhanced.     

FRIEDMAN-MEISELMAN REVISITED: A STUDY IN AUTOCORRELATION

The Durbin-Watson test is shown to reject the hypothesis of independent disturbances in the well known Friedman-Meiselman study. To cope with this the models have been re-estimated by maximum likelihood assuming an autoregressive disturbance process. The resulting estimates are consistent with Leijonhufvud's analysis of the economics of Keynes. Large sample methods have been applied in a highly exploratory spirit since for the sample sizes involved such methods may not be superior to ones adopted by Friedman-Meiselman. Our results imply that the Friedman-Meiselman estimates must be interpreted with caution. This is particularly acute for the 1933–1938 depression period.     

WHY ARE BETTER SEATS “UNDERPRICED”?

Faced with competition, one's behavior often depends on that of his competitors. The determination of price is one response to competition, and an important one indeed. But it is not the only one. All contracting parties may gain, if price can be reduced to encourage restraints on behavior. This paper shows that "behavior which restrains behavior" may be effectively induced by the simple expedient of a reduction in price.     

Population and family planning in developing countries: the employer's role

The overall population problem of the world is discussed briefly. The author asserts that rapid population growth has serious social and political implications and imposes serious restraints on economic progress. It is also linked to problems of urbanization. Family planning is a way out. The state alone is not enough to make family planning successful, it must be supported by the different segments of society. Employers have a major social responsibility in this respect. After this general introduction, and the assertion of the basic role of the employer in family planning programs, the author deals with the specific situation in India in terms of 1) its population problem, 2) progress and impact of the Indian family planning program, and 3) the role of employers in the promotion of family planning in India; a detailed section is devoted to the family planning centers of the Tata group of companies (Tata textile units, chemicals, iron and steel, engineering and locomotive, etc.). The author enumerates the measures to promote effective participation by employers, which include 1) an organized framework, 2) assistance to employers, and 3) removal of disincentives. The author concludes by saying that the efforts of employers to limit population growth need to be supplemented by international cooperation and action.