Unit roots and double smooth transitions

Techniques for testing the null hypothesis of difference stationarity against stationarity around some deterministic function have received much attention. In particular, unit root tests where the alternative is stationarity around a smooth transition in a linear trend have recently been proposed to permit the possibility of non-instantaneous structural change. In this paper we develop tests extending such an approach in order to admit more than one structural change. The analysis is motivated by time series that appear to undergo two smooth transitions in the linear trend, and the application of the new tests to two such series (average global temperature and US consumer prices) highlights the benefits of this double transition extension.     

Time use studies for leisure analysis

There is a growing interest in, time allocation research. Particularly by government statistical bodies. Papers in this issue, briefly highlighted in this introduction, make a small contribution to fulfilling a need for wider exposure of time use literature. The included papers do two things. First, they identify issues related to the collection and analysis of time use data. Second, they show how time use data can be effectively applied to improve one's understanding of significant issues.     

Planning—Satisfaction and productivity

The areas of worker satisfaction and productivity have been of continual importance to managers of all types of organizations. Unfortunately, the analysis of these topics have usually been done in a segmented manner. This article attempts to develop a total conceptual scheme for planning to increase worker satisfaction and employee productivity. Both internal work and external environmental components are included in the models which examine social psychological, physical, and environmental components of the worker's life in a total system's approach.     

Depression and Anger Trajectories During the Transition to Adulthood

The current study examined within‐person (transitions in living situation and parent status) and between‐persons (age, gender, parent education) predictors of trajectories of depressive and angry symptoms in 577 university graduates (ages 20 to 29) tracked for 7 years. Multilevel models determined that depressive and angry symptoms declined on average. Depressive symptoms were associated with leaving home when younger and living with parents when older. Becoming a parent was associated with increased anger, especially in mothers. These results were obtained after controlling for the effects of marriage and unemployment. Leaving home and parenthood may be turning points that are associated with shifts in trajectories of well‐being, depending on stable characteristics such as age and gender.     

Georges gurvitch and the dialectic of sociological knowledge

This is a translation of the “Preface” and “Introduction” to Georges Gurvitch'sDialectique et Sociologie, published in Paris by Flammarion in 1962. It appears here for the first time in English. The translator's remarks place Georges Gurvitch's dialectical method in an historical and theoretical context, and criticize some of the major assumptions of Gurvitch's position. I am grateful to the Librairie Ernest Flammarion for its kind permission to reproduce these pages. I wish to thank Ian and Evelyn Daix-Jones and Nathalie Babel Brown for their help in rendering Gurvitch's thought into English. The work is copyright Flammarian Publishers.     

To Share or Not to Share: When Do Toddlers Respond to Another's Needs?

The developmental origins of sharing remain little understood. Using procedures adapted from research on prosocial behavior in chimpanzees, we presented 18- and 25-month-old children with a sharing task in which they could choose to deliver food to themselves only, or to both themselves and another person, thereby making it possible for them to share without personal sacrifice. The potential recipient, a friendly adult, was either silent about her needs and wants or made them explicit. Both younger and older toddlers chose randomly when the recipient was silent. However, when the recipient vocalized her desires 25-month-olds shared whereas younger children did not. Thus, we demonstrate that children voluntarily share valued resources with others by the end of the second year of life, but that this depends on explicit communicative cues about another's need or desire.     

LOPSIDED REASONING ON LOPSIDED TESTS AND MULTIPLE COMPARISONS

For those who have not recognized the disparate natures of tests of statistical hypotheses and tests of scientific hypotheses, one‐tailed statistical tests of null hypotheses such as ?≤ 0 or ?≥ 0 have often seemed a reasonable procedure. We earlier reviewed the many grounds for not regarding them as such. To have at least some power for detection of effects in the unpredicted direction, several authors have independently proposed the use of lopsided (also termed split‐tailed, directed or one‐and‐a‐half‐tailed) tests, two‐tailed tests with α partitioned unequally between the two tails of the test statistic distribution. We review the history of these proposals and conclude that lopsided tests are never justified. They are based on the same misunderstandings that have led to massive misuse of one‐tailed tests as well as to much needless worry, for more than half a century, over the various so‐called ‘multiplicity problems’. We discuss from a neo‐Fisherian point of view the undesirable properties of multiple comparison procedures based on either (i) maximum potential set‐wise (or family‐wise) type I error rates (SWERs), or (ii) the increasingly fashionable, maximum potential false discovery rates (FDRs). Neither the classical nor the newer multiple comparison procedures based on fixed maximum potential set‐wise error rates are helpful to the cogent analysis and interpretation of scientific data.