Rational forecasts: On confirming ambiguity as the mother of conformity

The Rational Expectations Hypothesis claims that all available information is used in making forecasts. We contend that one of the pieces of information used by forecasters is the previous forecasts of others. Psychologists have demonstrated that under conditions of ambiguous stimuli. individuals frequently adapt their individual opinions so as to conform to peer opinions. Thus, we develop a Convergent Expectations Hypothesis, in which forecasters incorporate previous forecasts of other agents in forming their own expectations. The hypothesis is tested using data from six forecaster groups for four time periods. In all four time periods, forecasters appear to make considerable use of the prior consensus forecast in developing their own predictions. The resulting expectations may still be ‘rational’ in that there are psychological and perhaps financial benefits to conforming to the forecasts of professional peers.     

Immediate Memory for Mismatched Speech and Representational Gesture Across Development

Two experiments examined how 7- and 8-year-old children, 9- and 10-year-old children, and adults process mismatched, task-related speech and gesture differently as a function of development. Participants watched videotapes of children speaking and gesturing about the concept of conservation. Using a recognition paradigm, we assessed immediate memory for information conveyed in mismatched speech and gesture. In Experiment 1, we used recognition of verbal statements to probe participants' memory, whereas in Experiment 2, we used recognition of gestural statements to probe memory. When probed with verbal statements in Experiment 1, 9- and 10-year-old children failed to retrieve gestured information. When probed with gestural statements in Experiment 2, 9- and 10-year-old children failed to retrieve verbal information. In contrast, the younger children and adults showed retrieval of both verbal and gestural information across both recognition methods in Experiments 1 and 2. These results suggest a U-shaped function with the 9- and 10-year-old children showing a limitation in the ability to process contradictory messages simultaneously conveyed in two modalities. Implications for identifying a transitional period in the development of representational skills are discussed.     

Fertility trends in Australia

Using published data from the Australian vital registration and census systems, several time series are compiled: crude birth rates from the 1860s; fertility rates from the 1880s; age-specific and parity-specific measures from the 191Os; cumulative fertility measures by birth year of parent beginning with the 1890s; and cumulative fertility measures for marriages by year contracted from the 1910s.The decline in fertility to the 1930s, the upswing to 1961, and declines thereafter revealed by annual fertility measures show far more variation than do measures of total generation fertility—2.7 children per woman born in 1893–95, 2.3 1906–10, 2.8 1921–25, and perhaps 3.0 for women born in the 1930s. Both annual and generation measures show a younger age at parenthood, a decrease in childlessness, and progressively fewer large families. In the light of present experience, it seems not unreasonable to project generation fertility of 2.5 children, implying a crude birth rate of about 20 per thousand for the next fifteen years or so.     

Healthy children in families affected by AIDS: Epidemiological and psychosocial considerations

Traditional means of conceptualizing the psychosocial impact of AIDS have emphasized infected individuals out of their natural context AIDS occurs not simply within hospitals but within families. A secondary morbidity occurs within a family system when one of its members is infected. Clinical experience suggests that non-infected children within families with AIDS are at significant risk for poor developmental outcomes as a consequence of the skewing of familial resources. Children living in families who have a member infected by HIV are impacted by isues such as stigma, isolation, abandonment, and death. This article explores the epidemiology of this child population and risk factors that render them vulnerable. Social workers are in a unique position to identify and serve these children in such diverse settings as schools, welfare agencies, and hospitals. Suggested interventions based on the developmental stage of the child are discussed as are implications for policy formation and program development.     

Appraising Cultural Identity in Career-Development Assessment and Counseling

Career-Development Assessment and Counseling (C-DAC) systematically bridges career theory and practice. Integrating differential, developmental, and phenomenological methods, the C-DAC model uses a comprehensive career assessment battery to help clients explore their roles, developmental stages and tasks, career attitudes and knowledge, values, and interests within their unique life contexts. The authors recommend elaborating the C-DAC model to formally appraise cultural identity in step one of the model and to consider cultural identity concerns throughout the C-DAC process. This should help counselors more clearly understand how cultural factors influence people's career development and vocational behavior.     

Total error in PES estimates of population

"We describe a methodology for estimating the accuracy of dual systems estimates (DSE's) of population, census estimates of population, and estimates of undercount in the census. The DSE's are based on the census and a post-enumeration survey (PES). We apply the methodology to the 1988 dress rehearsal census of St. Louis and east-central Missouri and we discuss its applicability to the 1990 [U.S.] census and PES. The methodology is based on decompositions of the total (or net) error into components, such as sampling error, matching error, and other nonsampling errors. Limited information about the accuracy of certain components of error, notably failure of assumptions in the 'capture-recapture' model, but others as well, lead us to offer tentative estimates of the errors of the census, DSE, and undercount estimates for 1988. Improved estimates are anticipated for 1990." Comments are included by Eugene P. Ericksen and Joseph B. Kadane (pp. 855-7) and Kenneth W. Wachter and Terence P. Speed (pp. 858-61), as well as a rejoinder by Mulry and Spencer (pp. 861-3).     

Error models for official mortality forecasts

"The Office of the Actuary, U.S. Social Security Administration, produces alternative forecasts of mortality to reflect uncertainty about the future.... In this article we identify the components and assumptions of the official forecasts and approximate them by stochastic parametric models. We estimate parameters of the models from past data, derive statistical intervals for the forecasts, and compare them with the official high-low intervals. We use the models to evaluate the forecasts rather than to develop different predictions of the future. Analysis of data from 1972 to 1985 shows that the official intervals for mortality forecasts for males or females aged 45-70 have approximately a 95% chance of including the true mortality rate in any year. For other ages the chances are much less than 95%."     

Source Attribution of Food-Borne Zoonoses in New Zealand: A Modified Hald Model

A Bayesian approach was developed by Hald et al .^{( 1 )} to estimate the contribution of different food sources to the burden of human salmonellosis in Denmark. This article describes the development of several modifications that can be used to adapt the model to different countries and pathogens. Our modified Hald model has several advantages over the original approach, which include the introduction of uncertainty in the estimates of source prevalence and an improved strategy for identifiability. We have applied our modified model to the two major food-borne zoonoses in New Zealand, namely, campylobacteriosis and salmonellosis. Major challenges were the data quality for salmonellosis and the inclusion of environmental sources of campylobacteriosis. We conclude that by modifying the Hald model we have improved its identifiability, made it more applicable to countries with less intensive surveillance, and feasible for other pathogens, in particular with respect to the inclusion of nonfood sources. The wider application and better understanding of this approach is of particular importance due to the value of the model for decision making and risk management.     

Understanding Consumer Attitudes Toward Food Technologies in Canada

This article reports a study on consumer attitudes to 21 food and nonfood technologies in Canada. The study involves repertory grid interviews with 36 food consumers, the data from which are analyzed using generalized Procrustes analysis. Results highlight the role of perceived risk and perceived benefit in determining the acceptability of the technologies, with individual technologies lying along a continuum between the two. For technology as a whole and the 21 specific technologies, the perceived risk and perceived benefit constructs were the dominant determinants of consumer acceptability. While perceptions of perceived risk and perceived benefit differed between individual respondents, there were very limited consistent relations with a range of sociodemographic variables.     

Data integration in the evaluation of juvenile justice education

This article discusses the Juvenile Justice Educational Enhancement Program's evaluation of juvenile justice education through the integration of multiple data sources. Validation of best practices and the corresponding effect of these practices on community reintegration require the development of a comprehensive database of program-level and individual-level indicators from several sources. These sources include the Florida Department of Education, the Florida Department of Juvenile Justice, the Florida Department of Law Enforcement, the Florida Department of Corrections, and the Juvenile Justice Educational Enhancement Program's own educational quality assurance and pre-/posttest data. This article examines the methodological, political, and bureaucratic obstacles encountered in this effort. Evaluation research analyses are also explored with an emphasis on the meaning of outcome measures relative to causal issues of time order, the modeling of events, and analytic strategy. The article provides a framework for future juvenile justice educational evaluation and a critical examination of problems encountered in integrating data sources for the purpose of outcome evaluation.