Overconfident investors and probability misjudgments

This paper explores systematic distortions of subjective probabilities by overconfident investors. In agreement with many non-expected utility theories, our devised setup acknowledges nonlinear weighting of physical probabilities by both rational and overconfident investors. Overconfidence – assumed to be higher after a history of gains and lower after a history of losses – changes these probability transformations. Using US asset price data, overconfident investors are found to be more optimistic than rational investors about future prospects.     

Urn Sampling and the Proportional Hazard Model

This paper investigates the urn sampling analogue for the score statistic relating survival to covariates assuming a proportional hazard model. The exact permutation distribution can be calculated as well as the exact low order moments for arbitrary censoring patterns. The asymptotic distribution of the score statistic is an easy consequence. The method is naturally extended to deal with the multivariate case, time varying covariates and interval censoring. Finally the relationship between the censoring process, the survival times and covariates are studied considering different reference sets for the distribution of the score statistic. Some assumptions about the censoring process are investigated and as a consequence the effect of censoring is clarified.     

Double Sampling Designs in Multivariate Linear Models with Missing Variables

We provide a method for finding the optimal double sampling plan for estimating the mean value of a continuous outcome. It is assumed that the fallible and true outcome data are related by a multivariate linear regression model where only some of the explanatory variables are sampled. Conditions under which double sampling is preferred over standard sampling plans are determined. An application of the method to a well-known data set on air pollution is presented.     

Testing for order among K populations: theory and examples

Testing for stochastic order among K populations is a common and important problem in statistical practice. It arises in the analysis of both planned experiments and observational studies. The authors develop a new nonparametric test for order among K populations that can accommodate any stochastic ordering. The test is based on a maximally selected chi‐bar‐square statistic. The authors find its limiting distribution and use simulations to derive critical values. Three important examples are used to illustrate the applicability of the general method. The authors find that the new tests outperform the existing methods in many practical cases. The Canadian Journal of Statistics 38: 97–115; 2010 © 2009 Statistical Society of Canada     

Stratified Double Sampling with Continuous Outcomes: Design and Analysis

We provide a method for estimating the sample mean of a continuous outcome in a stratified population using a double sampling scheme. The stratified sample mean is a weighted average of stratum specific means. It is assumed that the fallible and true outcome data are related by a simple linear regression model in each stratum. The optimal stratified double sampling plan, i.e. , the double sampling plan that minimizes the cost of sampling for fixed variances, or alternatively, minimizes the variance for fixed costs, is found and compared to a standard sampling plan. The design parameters are the total sample size and the number of doubly sampled units in each stratum. We show that the optimal double sampling plan is a function of the between-strata and within-strata cost and variance ratios. The efficiency gains, relative to standard sampling plans, under broad set of conditions, are considerable.     

New tests for stochastic order with application to case control studies

It is shown that if a binary regression function is increasing then retrospective sampling induces a stochastic ordering of the covariate distributions among the responders, which we call cases, and the non-responders, which we call controls. We also show that if the covariate distributions are stochastically ordered then the regression function must be increasing. This means that testing whether the regression function is monotone is equivalent to testing whether the covariate distributions are stochastically ordered. Capitalizing on these new probabilistic observations we proceed to develop two new non-parametric tests for stochastic order. The new tests are based on either the maximally selected, or integrated, chi-bar statistic of order one. The tests are easy to compute and interpret and their large sampling distributions are easily found. Numerical comparisons show that they compare favorably with existing methods in both small and large samples. We emphasize that the new tests are applicable to any testing problem involving two stochastically ordered distributions.     

Sources of Volunteer Motivation: Transformational Leadership and Personal Motives Influence Volunteer Outcomes

We examined the separate influences of volunteers' personal motives and their team leaders' behaviors on volunteer satisfaction and contributions, along with mediating processes suggested by self‐determination theory. Participants were 302 volunteers who worked in teams at various sites through a central agency. As predicted, both personal motives for volunteering and transformational leadership influenced volunteer satisfaction through enhanced work meaningfulness and higher‐quality team relationships. However, motives that predicted volunteer contribution were different from those that predicted satisfaction. Whereas satisfaction was positively associated with motives concerning esteem enhancement and value expression, contribution was positively associated with motives to gain understanding and negatively related to motives pertaining to esteem enhancement and social concerns. Transformational leadership was positively associated with volunteer satisfaction, but not with volunteer contributions. The theoretical ramifications of these findings are discussed, along with practical implications for the recruitment and retention of volunteers.     

IS THE ENDOWMENT EFFECT AN EXPECTATIONS EFFECT?

A hallmark result within behavioral economics is that individuals' choices are affected by current endowments. A recent theory due to Kőszegi and Rabin ( 2006 , Quarterly Journal of Economics, 121, 1133–1165) explains such endowment effect with a model of expectations‐based reference‐dependent preferences. Departing from past work, we conduct complementary experiments to disentangle expectations—verified probabilistic beliefs held by subjects—from other features of endowment—such as “assignment” to a good—hence allowing us to compare the effect of expectations with that of other variations. While mere assignment can affect choices, we do not find a large role in the effect for Kőszegi–Rabin expectations.     

Improving an estimator of Hsieh and Turnbull for the binormal ROC curve

The estimator of Hsieh and Turnbull (1996) for the binormal receiver operating characteristic (ROC) curve is extended from grouped to ungrouped data. The new estimator is shown to be consistent and asymptotically normally distributed, and simulation results show that it outperforms Hsieh and Turnbull's original estimator.     

Daily street life in the inner city of Prague under transformation: the visual experience of socio-spatial differentiation and temporal rhythms

The paper is concerned with the everyday manifestation of increasing social, lifestyle and cultural diversity in the transforming inner city of Prague. The Smíchov neighbourhood and particularly its central hub, the Anděl junction, were chosen as the focus of the study. The regeneration dynamics during the post-socialist transformation make this place particularly interesting for an inquiry into the interplay of the social and physical environment, into the interactions of changing urban landscapes and people's everyday practices. Particular attention is paid to the character of ordinary daily street life, to the users of urban space and to the manifestation of close-knit social, spatial and temporal diversity in the close vicinity of the Anděl hub. The paper concludes with the necessity of including the temporal dimension of space in urban planning and design practice. Methodologically the case study derives principally from direct observation of neighbourhood life and users, but also draws on the extensive research previously conducted in the neighbourhood by the authors and from intensive experience of living in the area.