Sequential sampling in the search for new shared species

In microbial sciences, as well as other disciplines, it is often valuable to sample communities in a sequential or group sequential manner, in order to determine their structure or their similarity. We develop sequential sampling procedures to accomplish this by first assuming that one observation is drawn with replacement from each population at a time. Suppose that the sampling is terminated after n pairs of observations and k shared species were discovered, and assume that we receive payoff h(k)−cn, where h(k) is non-decreasing and the sampling cost c is non-negative. Similar to Rasmussen and Starr (1979), we show that an optimal stopping rule exists if h(k+1)−h(k) is non-increasing. An analogous result holds for group sequential sampling. This leads to using an estimate of the probability of discovering new shared species as a stopping indicator for comparing two populations with respect to the similarity index. We show by simulation and real examples that this is a feasible approach which can help to reduce the sample size.     

Employment deconcentration in the nonmetropolitan migration turnaround

Since 1970, metropo1itan-to-nonmetropo1itan migration has substantially exceeded the corresponding and historically greater stream of migrants from nonmetropolitan to metropolitan areas. Previous research has concentrated on the changes in retirement mobility, growth of recreation and tourism, and residential preferences responsible in part for the new trends in population distribution. Relatively less attention has been paid to the corresponding phenomenon of the deconcentration of persons who remain actively engaged in the labor force. This research uses data from the Continuous Work History Sample merged with a file of county characteristics to examine trends in location of employed workers from 1960 to 1975. The analyses document changes of county of employment that parallel the trends in general population mobility. The CWHS data show increased movement of employed workers out of the largest SMSAs and into the smaller SMSAs and into both adjacent and nonadjacent nonmetropolitan counties. These data also indicate that the rate of change is greatest for nonadjacent counties. Both increased metropolitan outmovement and decreased nonmetropolitan outmovement are significant in producing the observed net changes.     

Smith's Sentiments (1759) and Wright's Passions (1601): the beginnings of sociology

Treatments of sources of Adam Smith's sociological theory of the self and associated ideas in The Theory of Moral Sentiments typically refer to classical antecedents or the work of his teacher Francis Hutcheson or his contemporary David Hume. During the seventeenth century, however, many books on the passions were published in London that arguably constitute an important but neglected source of Smith's treatment of moral sentiments. These works are largely forgotten today but at the time were widely read. They are not philosophical, partly devotional and predominantly psychological. Although Smith does not refer to these works his argument resembles theirs in many places. The importance of the seventeenth-century books on the passions, apart from their role in the history of psychology, is their bearing on contemporary economic practices. In this paper the connections between Smith and one of these books, Thomas Wright's The Passions of the Minde in Generall, are indicated.     

What's in a Name?: Preference for "Black" versus "African-American" among Americans of African Descent

This research note examines the preferences of Americans ofAfrican descent for the label "black" versus "African-American."Racial labels have long been associated with majority-groupattitudes toward minority-group members, and minorities themselveshave changed their preferred terminology over time. We tracethe evolution of racial labels from "Negro" to "black" to "African-American"and examine predictors of terminological preference among anational sample of Americans of African descent. Our respondentsare nearly equally divided in their preference for the label"black" versus "African-American." Significant correlates orpredictors of terminological preference include the racial compositionof the grammar school that respondents attended, respondents’degree of racial group consciousness, and age, region, and sizeof city of residence.     

Evaluating Stimulus-Stimulus Pairing and Direct Reinforcement in the Establishment of an Echoic Repertoire of Children Diagnosed with Autism

Many children with autism do not imitate adult vocalizations, an important skill in learning to talk. Pairing adult vocalizations with preferred stimuli has been shown to increase free-operant vocalizations but effects are temporary; thus, direct reinforcement may be necessary to establish durable vocal behaviors. In Experiment 1, directly reinforced echoic responses did not increase following stimulus-stimulus pairings in three children with autism. Similarly, pairings did not increase free-operant vocalizations in Experiment 2, a replication of Miguel et al. (2002). Experiment 3 demonstrated that shaping increased vowel frequency for one participant. Results suggest that variables are yet to be delineated that influence effectiveness of a stimulus-stimulus pairing procedure on vocalization frequency and acquisition of a verbal operant following such pairings.     

A test of uncertainty,expectations, and error response in two strike models

An information-uncertainty form of the Hicks strike model is used to test earlier work on the role of forecasts and uncertainty in determining strike activity. The expected zero coefficients for economic forecasts appear in preferred equations, but the expected positive coefficient for inflation uncertainty often appears as significantly negative. Alternative formulations and reasoning make the results appear somewhat more plausible. The performance of the Hicks model is contrasted with an updated Ashenfelter and Johnson model, which performs and predicts well without any untidy coefficients. Both models predict better than naive forecasting. Certain data and concept refinements are added to the testing of both analyses to bring them closer to the spirit of their models and to established research in wage determination and macroeconomics.     

Organized manufacturing for superior market performance

This article describes a series of case studies which show the global marketing benefits that can result from a strategic deployment of advanced manufacturing technology. The paper points out that a desirable collaboration between manufacturing and marketing is often not achieved. The authors then identify a number of factors that inhibit the rapid adoption of manufacturing technology for competitive advantage. This leads to a final section where recommendations are made for achieving a better linkage between technology and competitive strategy, and for facilitating the introduction of technology in the plant itself.     

Sources of geographic mobility among professional workers: A multivariate analysis

Using the 1960 Census of Population one-in-a-thousand sample, this study investigates determinants of geographic mobility among professional, technical, and kindred workers. Multiple regression analysis reveals that age accounts for most of the explained variance in mobility, followed by income, education, regional location, sex, family size, and marital status. Additional variables-class of worker, race, nativity, professional type, size of place and industry-add no significant increments to explained variance.More specifically, low income and high education stimulate mobility and increases in family size and age slacken it. Young married professionals move the most and farthest, males somewhat more than females. Mobility is greatest in the West, least in the Northeast. Age reduces or reverses contrasts between single and married, large and small families, high and low incomes, little and much education, and residents of East and West.Factor analysis suggests that migration is part of two orderly processes-occupational career mobility and family life cycle. The bearing of these findings on the relationship between geographic mobility and social integration for the middleclass in the United States is considered.