Detecting multiple change points in piecewise constant hazard functions

The National Cancer Institute (NCI) suggests a sudden reduction in prostate cancer mortality rates, likely due to highly successful treatments and screening methods for early diagnosis. We are interested in understanding the impact of medical breakthroughs, treatments, or interventions, on the survival experience for a population. For this purpose, estimating the underlying hazard function, with possible time change points, would be of substantial interest, as it will provide a general picture of the survival trend and when this trend is disrupted. Increasing attention has been given to testing the assumption of a constant failure rate against a failure rate that changes at a single point in time. We expand the set of alternatives to allow for the consideration of multiple change-points, and propose a model selection algorithm using sequential testing for the piecewise constant hazard model. These methods are data driven and allow us to estimate not only the number of change points in the hazard function but where those changes occur. Such an analysis allows for better understanding of how changing medical practice affects the survival experience for a patient population. We test for change points in prostate cancer mortality rates using the NCI Surveillance, Epidemiology, and End Results dataset.     

Blurring the Lines Between Civil Society,Volunteering and Social Movements. A Reflection on Redrawing Boundaries Inspired by the Spanish Case

Citizen participation is manifested through various concepts, such as activism, social movements, volunteering or civil society. The different ways of understanding popular engagement are often separated by delimitations that define them, particularly volunteering and civic action, as two highly differentiated forms of participation in the distinct academic disciplines: political science, volunteering studies, social movement studies or civil society theory. This article considers whether this basic theoretical differentiation can be problematised in the Spanish political context by exploring four paradigmatic cases of popular engagement, using qualitative case study methodology, specifically, a historic case from the 1990s and three more recent cases. It is hoped that the results of the study—which differentiates between organisational hybridity and fuzziness—will encourage reflection on the traditional boundaries between different forms of popular engagement.     

Episodic Volunteering at a Religious Megaevent

In preparation for Pope Francis's visit to Philadelphia and the 2015 World Meeting of Families, organizers looked for thousands of volunteers to help carry out these events. This is common for many one‐time and episodic events, such as large sporting events (from marathons to Special Olympics), arts and cultural events (such as festivals and concerts), and fundraising events. After the pope's visit, volunteers were asked to respond to a questionnaire about their experiences and the volunteer management of the event; 2,408 responded (34.4 percent). Data on motivation, who volunteered, recruitment, training, assignment, supervision, communication, satisfaction, and suggestions for improvement were elicited. We focused on episodic volunteering at a religious event and on a broad spectrum of issues pertaining to management of episodic volunteers. Our findings add to the knowledge regarding volunteer management and also add to conceptual understanding of the distinction between ongoing and episodic volunteers.     

Socioemotional wealth’s implications in the calculus of the minimum rate of return required by family businesses’ owners

This paper demonstrates that the minimum rate of return (k _e ) required by family business shareholders is inversely related to the emotional endowment presented in these firms. After reviewing the socioemotional wealth (SEW) literature, we find empirical support to justify that different SEW dimensions influence k _e . Findings from a population of 207 family firms show that the identification of family members with the firm and the renewal of family bonds with the firm through dynastic succession have consistently negative impacts on k _e , while family control and influence have significantly positive impacts on k _e .     

Welfare gains of the poor: An endogenous Bayesian approach with spatial random effects

We introduce a Bayesian instrumental variable procedure with spatial random effects that handles endogeneity, and spatial dependence with unobserved heterogeneity. We find through a limited Monte Carlo experiment that our proposal works well in terms of point estimates and prediction. We apply our method to analyze the welfare effects generated by a process of electricity tariff unification on the poorest households. In particular, we deduce an Equivalent Variation measure where there is a budget constraint for a two-tiered pricing scheme, and find that 10% of the poorest municipalities attained welfare gains above 2% of their initial income.     

A Dynamic Model of Product Quality and Pricing Decisions on Sales Response

This paper presents a dynamic model that examines the influence of price and customer perception of product quality on the sales rate of a firm producing durable goods. The sales rate of the firm is modeled as a function of its price, average product life, perceived quality, and market potential. Specifically, the model considers: (1) the process by which perceived quality is determined by including the effects of the average life of a product and quality weighted units in the market; (2) the time delay in the influence of actual quality on perceived quality; (3) the process by which demand (i.e., potential sales) is converted to realized sales due to the effects of price and perceived quality; and (4) the saturation effect and associated non-linearity in the demand function. The model presented is a reformulation and extension of the model originally proposed by Bass [2]. The validity of the model is tested using historical data on For Mustang.     

Trade and Factor Market Reforms in China

The benefits of the multi‐faceted liberalization of the Chinese economy can be seen in various indicators of economic development. The rate of growth of the economy, the flow of foreign investment in China, and rising quality of life are some of the indicators of gains from the liberalization process. Most of the research has focused on the role of trade reforms on the Chinese economy. There is, however, one unfinished agenda that has not been addressed adequately by policy makers as well as academia, i.e. labor‐sector reforms. In this paper, we analyze the effect of labor market liberalization in China using a Computable General Equilibrium (CGE) model. Most CGE models on China using a neoclassical approach assume that there is a single wage rate for the economy. This is a simplifying assumption and has strong implications. Studies show that inter‐industry wage differentials persist even after accounting for obvious explanations such as differences in human capital or job hazard. Inter‐industry structural rigidities in developing countries lead to wage differentials. In China, labor mobility from the rural to the urban sector is restricted. Furthermore, China is on its way to joining the WTO agreement. As a signatory to the WTO agreement, China would be required to reform its trade sector by eliminating tariffs. In this paper, we explicitly model wage differentials in the case of the Chinese economy. Various counterfactual experiments have been conducted to introduce efficiency by the removal of factor market differentials in China in the presence and absence of tariff and non‐tariff barriers. Our results indicate that factor market reforms are essential to the realization of full gains from accession to the WTO agreement.     

A resilience enhancing trauma-informed program for children and mothers in domestic violence shelters: A qualitative study

In domestic violence (DV) shelters, offering psychosocial support services to mothers and children is vital. The program ‘Time for Tony the Turtle’ has been developed for mothers and children residing in DV shelters in the Netherlands. It aims to foster attachment and regulation skills, which can also prepare for trauma treatment if sought after later on. This qualitative study explores the experiences of mothers, children and professionals with the program and its perceived impact and what components function as facilitators and barriers in the implementation of such a program in DV crisis shelters in the Netherlands. We conducted in-depth interviews with 15 mothers, 11 children and 18 professionals from three organizations offering DV shelters. We used thematic analysis to identify patterns of meaning in the interviews. Mothers, children and professionals valued that the program provided a calm moment for reflection in hectic times and that the playfulness in which the program addressed trauma-related topics. However, mothers find it difficult to attend the program in the beginning of their shelter stay, therefore hampering the applicability of the program. Our findings suggest that integrating the topic of discussing father in a program in crisis shelters is complex and deserves more attention.     

Genetic variants in ATP6 and ND3 mitochondrial genes are not associated with aggressive prostate cancer in Mexican–Mestizo men with overweight or obesity

Mitochondrial defects have been related to obesity and prostate cancer. We investigated if Mexican–Mestizo men presenting this type of cancer, exhibited somatic mutations of ATP6 and/or ND3.Body mass index (BMI) was determined; the degree of prostate cancer aggressiveness was demarcated by the Gleason score. DNA from tumor tissue and from blood leukocytes was amplified by the polymerase chain reaction and ATP6 and ND3 were sequenced. We included 77 men: 20 had normal BMI, 38 were overweight and 19 had obesity; ages ranged from 52 to 83. After sequencing ATP6 and ND3, from DNA obtained from leukocytes and tumor tissue, we did not find any somatic mutations. All changes observed, in both genes, were polymorphisms. In ATP6 we identified, in six patients, two non-synonymous nucleotide changes and in ND3 we observed that twelve patients presented non-synonymous polymorphisms. To our knowledge, this constitutes the first report where the complete sequences of the ATP6 and ND3 have been analyzed in Mexican–Mestizo men with prostate cancer and diverse BMI. Our results differ with those reported in Caucasian populations, possibly due to ethnic differences.