Estimation of cumulative incidence functions when the lifetime distributions are uniformly stochastically ordered

In the competing risks problem an important role is played by the cumulative incidence function (CIF), whose value at time t is the probability of failure by time t from a particular type of risk in the presence of other risks. Assume that the lifetime distributions of two populations are uniformly stochastically ordered. Since this ordering may not hold for the empiricals due to sampling variability, it is natural to estimate these distributions under this constraint. This will in turn affect the estimation of the CIFs. This article considers this estimation problem. We do not assume that the risk sets in the two populations are related, give consistent estimators of all the CIFs and study the weak convergence of the resulting processes. We also report the results of a simulation study that show that our restricted estimators outperform the unrestricted ones in terms of mean square error. A real life example is used to illustrate our theoretical results.     

Estimation of extreme quantiles from heavy and light tailed distributions

In Gardes et al. (2011), a new family of distributions is introduced, depending on two parameters τ$\tau$ and θ$\theta$, which encompasses Pareto-type distributions as well as Weibull tail-distributions. Estimators for θ$\theta$ and extreme quantiles are also proposed, but they both depend on the unknown parameter τ$\tau$, making them useless in practical situations. In this paper, we propose an estimator of τ$\tau$ which is independent of θ$\theta$. Plugging our estimator of τ$\tau$ in the two previous ones allows us to estimate extreme quantiles from Pareto-type and Weibull tail-distributions in an unified way. The asymptotic distributions of our three new estimators are established and their efficiency is illustrated on a small simulation study and on a real data set.     

Promoting Civil Society in Contemporary Poland: Gendered Results of Institutional Changes

This paper is a contribution to the ongoing discussion concerning factors determining the development of civil society in a post-state socialist context. It examines the financial mechanisms designed to promote civic engagement in Poland, including EU grants and the so-called ‘percentage law’ that allows citizens to support NGOs of their choice with 1 % of their taxes. A detailed analysis of these mechanisms demonstrates that they are advantageous for some types of non-governmental organizations and not for others. Instead of enhancing the situation of the whole sector, they tend to support NGOs that already have substantial resources and hold a strong position vis-à-vis the state. Moreover, organizations and groups fighting for issues considered to be controversial—such as women’s NGOs advocating for the right to abortion or criticizing authorities for their lack of concern when it comes to violence against women—have limited chances to gain financial support from both the state and those sources that are independent from the state. This shows how seemingly gender-neutral institutional arrangements may bring gendered results. The following analysis is based on available statistics (several reports provided by the Klon-Jawor Association, Social Diagnosis Reports from 2007 and 2011) and qualitative data (semi-structured interviews and discourse analysis of the Polish media).     

Tests for noncorrelation of two multivariate ARMA time series

In many situations, we want to verify the existence of a relationship between multivariate time series. In this paper, we generalize the procedure developed by Haugh (1976) for univariate time series in order to test the hypothesis of noncorrelation between two multivariate stationary ARMA series. The test statistics are based on residual cross-correlation matrices. Under the null hypothesis of noncorrelation, we show that an arbitrary vector of residual cross-correlations asymptotically follows the same distribution as the corresponding vector of cross-correlations between the two innovation series. From this result, it follows that the test statistics considered are asymptotically distributed as chi-square random variables. Two test procedures are described. The first one is based on the residual cross-correlation matrix at a particular lag, whilst the second one is based on a portmanteau type statistic that generalizes Haugh's statistic. We also discuss how the procedures for testing noncorrelation can be adapted to determine the directions of causality in the sense of Granger (1969) between the two series. An advantage of the proposed procedures is that their application does not require the estimation of a global model for the two series. The finite-sample properties of the statistics introduced were studied by simulation under the null hypothesis. It led to modified statistics whose upper quantiles are much better approximated by those of the corresponding chi-square distribution. Finally, the procedures developed are applied to two different sets of economic data.     

Estimation of parameters of the inverse gaussian-weibull mixture model

The main objective of this work is to estimate the 5-dime-nsional vector of parameters (p,μ,λ,α,c) of the mixture of an Inverse Gaussian IG(μ,λ) and Weibull W(α,c) distributions with mixing proportion p. We use the maximum Likelihood method (MLM) and the weighted maximum likelihood method (WMLM), both under the sampling schemes suggested by Hosmer (1973). Simulation study shows that the WMLM performs best, when Hosmer's model 2 is used, in the sense of minimizing the mean square error.     

Using the Concepts of Hermeneutical Injustice and Ideology to Explain the Stability of Ancient Egypt During the Middle Kingdom

This paper argues that the relative stability of ancient Egyptian society during the Middle Kingdom (c.2055 – 1650 BC) can in part be explained by referring to the phenomenon of hermeneutical injustice, i.e., the manner in which imbalances in socio-economic power are causally correlated with imbalances in the conceptual scheme through which people attempt to interpret their social reality and assert their interests in light of their interpretations. The court literature of the Middle Kingdom is analyzed using the concepts of hermeneutical injustice and ideology. It is argued that while it is true that there was room for maneuver and for internal critique, the efficacy of internal critique was hindered by the structure of the intellectual discourse of Middle Kingdom Egypt. This intellectual discourse was suitable for the interpretation of social reality in a way that allowed the elites to assert their interests, but it was not suitable for the interpretation of social reality in a way that accorded with the interests of the exploited peasantry.     

Perceived Racial Discrimination in Health Care and Race Differences in Physician Trust

Racial discrimination in health care is more often perceived by racial minority patients than by whites. In this study, we explored whether two types of perceived racial discrimination, perceptions that the healthcare system is racially biased in general (perceived institutional racial discrimination) and perceptions that one has personally encountered racial discrimination while seeking health care (perceived interpersonal racial discrimination), mediated racial differences in patients’ trust in physicians. We examined this in a sample of black (N = 127) and white (N = 303) patients being treated in two Veterans Affairs orthopedic clinics for advanced osteoarthritis. Patients completed measures of perceived institutional and interpersonal racial discrimination in health care before meeting with an orthopedic surgeon and a measure of physician trust after the visit. Using a multiple mediator bootstrapping procedure, we tested whether perceived institutional and/or interpersonal racial discrimination mediated the association between race and trust. Compared to whites, blacks reported lower physician trust (M = 4.00 vs. 4.17, β = ?0.15, 95 % CI = ?0.25, ?0.05), more perceived institutional racial discrimination (M = 3.13 vs. 2.60, β = 0.43, 95 % CI = 0.25, 0.61), and more perceived interpersonal racial discrimination (M = 1.94 vs. 1.21, β = 0.60, 95 % CI = 0.47, 0.74). Perceived interpersonal, but not institutional, racial discrimination mediated the race difference in physician trust and accounted for 55 % of the variance. Our finding that lower physician trust among black patients than white patients was explained by perceptions of interpersonal racial discrimination in health care suggests that issues of racial discrimination may need to be addressed in order to foster minority patients’ trust in physicians.     

EDLP versus Hi–Lo pricing strategies in retailing—a state of the art article

The pricing strategy is seen as one of the five most important priorities in retail management. Over the past years, price wars have emerged and price has become an even more focal point of retailers’ agendas. Especially grocery retailers operate on very low margins and have fallen into a price-promotion trap, pressured both by competition and consumers. In times of intensive competition it is getting even more important for retailers to focus on profitable and successful pricing strategies. Furthermore, retailers act under complex circumstances, especially because of broad assortments, and should therefore define a clear framework for their pricing strategy. There are several studies which have been published on pricing strategy in retailing during the last years, but no comprehensive literature review of this topic with its determinants and outcomes exists. Based on the theoretical and conceptual foundations of pricing strategy in retailing, all relevant conceptual and empirical studies are analyzed. First, the different definitions of pricing strategy in retailing are examined and systemized. Furthermore, a division into studies on determinants and outcomes of pricing strategy in retailing is included followed by a discussion of main and further results. Based on this analysis of the existing literature, avenues for further research are identified and prioritized.