Events that Trigger Poverty Entries and Exits*

Objective. This article examines how events—such as changes in household composition, employment status, disability status, and economic conditions—affect poverty entries and exits. We also examine whether the role these events play in poverty transitions differs in the pre‐ and post‐welfare‐reform periods. Methods. The analysis uses discrete‐time multivariate hazard models along with monthly, longitudinal data from the 1988, 1990, and 1996 panels of the Survey of Income and Program Participation (SIPP). Results. Analyses show that many events are related to the likelihood of entering and exiting poverty. Of the trigger events examined, individuals living in households that experience a loss or gain of employment are the most likely to enter and exit poverty. We also find that changes in employment are more important in the 1996 to 1999 time period—after welfare reform—than in the 1988 to 1992 time period—prior to welfare reform. Finally, changes in household composition, disability status, and educational attainment are found to play a role in throwing people into poverty and helping them exit from poverty in both time periods. Conclusions. There is no single path into or out of poverty, suggesting that multiple policies can be considered to help alleviate poverty.     

Infants' Ability to Distinguish Between Intentional and Accidental Actions and Its Relation to Internal State Language

The experiment reported here investigated infants' concept of intention, as well as the relation among intention understanding, general productive vocabulary, and internal state language production during the 2nd year. Results from an imitation task indicated that 18‐month‐olds are better able to differentiate between intentional and accidental actions than 14‐month‐olds. Although there was no relation between infants' performance on the intention task and their general productive vocabulary, internal state language production at 30 months was predicted by infants' ability to differentiate between intentional and accidental actions about a year earlier. These findings shed light on the developmental progression of infants' concept of intention, as well as on the continuity between infants' understanding of intentional action and their ability to use internal state words.     

Prediction theory for autoregressivemoving average processes

This paper reviews statistical prediction theory for autoregressive-moving average processes wing techniques developed in control theory. It demonstrates explicitly the connectioluns between the statistical and control theory literatures. Both the forecasting problem and the Single extraction problem am considered, udng linear least squares methods. Whereas the classical Statistical theory developed by Wiener and Kolmogomv is restricted to stationary stochaotic processes, the recursive techniques known as the Kalman filter are shown to provide a satisfactory treatment of the difference-stationary care and other more general cases. Complete results for non-invertible moving averages are also obtained.     

Mark-resighting analysis of a California gull population

California gulls ( Larus californicus ) of known age and sex were censused on their breeding colony in 1979, 1980 and 1984 through 1993. Ages of 235 males and 196 females ranged from 4 to 27 years. Age classes used in the analysis were limited to 17, 4 through 19, and 20 or more as a final age category because data on gulls over 20 were sparse. Survival declined with age in a way that was parsimoniously modelled with a quadratic function. Other factors, sex and time, did not explain any variation in survival. Resighting depended on age, sex and time. Younger adults skipped breeding more frequently than did older adults, and females skipped breeding more frequently than did males. There was also good evidence for time dependence in resighting probability, but its inclusion in the model occurred at the expense of interpretability and precision. In a data set such as this, resighting probability may assume more importance than a mere 'nuisance parameter'. In this study, resighting history measured attendance at the breeding ground. In turn, attendance rates may be a manifestation of reproductive strategy, which can also have consequences for survival. In this situation, there may be heterogeneity in both survival and resighting probability that is unexplained by the model. While such complexity may well be a nuisance to deal with, it can also point to important biological questions.     

Evaluating the slavonian census of 1698 part II: A microsimulation test and extension of the evidence

An adjusted 17th C. census based on critical reading of the historical text is the basis for indirect estimation of uncounted persons. The census states no ages and excludes many categories of household residents. Microsimulation based on historically and ethnographically plausible rates and household formation scenarios produces simulated households that match the observable portions of households in the adjusted census. Microsimulation results permit estimation of the uncounted population, of the kinship and age composition of households under extant frontier conditions, and the probable future composition of households as the frontier stabilized and land shortage began to exert pressure for greater density and household complexity.     

Productivity indices and survival rate estimates from MAPS,a continent-wide programme of constant-effort mist-netting in North America

The Monitoring Avian Productivity and Survivorship (MAPS) programme is a cooperative effort to provide annual regional indices of adult population size and post-fledging productivity and estimates of adult survival rates from data pooled from a network of constant-effort mist-netting stations across North America. This paper provides an overview of the field and analytical methods currently employed by MAPS, a discussion of the assumptions underlying the use of these techniques, and a discussion of the validity of some of these assumptions based on data gathered during the first 5 years (1989-1993) of the programme, during which time it grew from 17 to 227 stations. Ageand species-specific differences in dispersal characteristics are important factors affecting the usefulness of the indices of adult population size and productivity derived from MAPS data. The presence of transients, heterogeneous capture probabilities among stations, and the large sample sizes required by models to deal effectively with these two considerations are important factors affecting the accuracy and precision of survival rate estimates derived from MAPS data. Important results from the first 5 years of MAPS are: (1) indices of adult population size derived from MAPS mist-netting data correlated well with analogous indices derived from point-count data collected at MAPS stations; (2) annual changes in productivity indices generated by MAPS were similar to analogous changes documented by direct nest monitoring and were generally as expected when compared to annual changes in weather during the breeding season; and (3) a model using between-year recaptures in Cormack-Jolly-Seber (CJS) mark-recapture analyses to estimate the proportion of residents among unmarked birds was found, for most tropical-wintering species sampled, to provide a better fit with the available data and more realistic and precise estimates of annual survival rates of resident birds than did standard CJS mark-recapture analyses. A detailed review of the statistical characteristics of MAPS data and a thorough evaluation of the field and analytical methods used in the MAPS programme are currently under way.     

The Turkish alevis

The Alevi comprise a specific ethnic group in Turkey of especial interest. In presenting a case study of an Alevi community in Ankara that arose out of internal urban migration, the present paper delineates the way in which the Alevis have moved away from constituting a counterculture during the period of the Ottoman period to comprising a working class subculture of great organizational and political potential in contemporary Turkey. The paper also describes the ethnic markedness of the Alevi community and the problems that arise out of this markedness.