Response surface methodology in quality improvement

Recent work has lead to development of robust parameter design which alleviates criticisms of the Taguchi approach. A dual response surface approach is discussed and illustrated.     

Teaching Survey Sampling Using Simulation

SURVEY is a computer program that simulates samples drawn from a hypothetical county. We use SURVEY in introductory and advanced sample survey classes to allow students to become involved in all stages of the sampling process, from designing the survey, to analyzing it, to dealing with nonresponse.     

CONCEPTS,THEORY, AND TECHNIQUES

The beta distribution is becoming more widely used in business applications and in economic model-building. A simple way to estimate the parameters of the univariate distribution and the general multivariate distribution would be useful but there appears to be no simple way of accomplishing this task. For example, the method of maximum likelihood does not yield tractable results. The method of moments presented in this paper is a practical way to obtain parameter estimates for the beta distribution. Explicit estimators are derived for the univariate and bivariate case and estimators are then inferred for the n-variate case. Empirical tests suggest that the method of moments may be used to establish useful estimates for these parameters. Also, estimates obtained by the method of moments may be used to develop bounds on the parameters so that computational techniques can be utilized with other estimation methods possessing more desirable properties.     

Directed Matching and Monetary Exchange

We develop a model of monetary exchange where, as in the random matching literature, agents trade bilaterally and not through centralized markets. Rather than assuming they match exogenously and at random, however, we determine who meets whom as part of the equilibrium. We show how to formalize this process of directed matching in dynamic models with double coincidence problems, and present several examples and applications that illustrate how the approach can be used in monetary theory. Some of our results are similar to those in the random matching literature; others differ significantly.