Parametric non-mixture cure models for schedule finding of therapeutic agents

We propose a phase I clinical trial design that seeks to determine the cumulative safety of a series of administrations of a fixed dose of an investigational agent. In contrast with traditional phase I trials that are designed solely to find the maximum tolerated dose of the agent, our design instead identifies a maximum tolerated schedule that includes a maximum tolerated dose as well as a vector of recommended administration times. Our model is based on a non-mixture cure model that constrains the probability of dose limiting toxicity for all patients to increase monotonically with both dose and the number of administrations received. We assume a specific parametric hazard function for each administration and compute the total hazard of dose limiting toxicity for a schedule as a sum of individual administration hazards. Throughout a variety of settings motivated by an actual study in allogeneic bone marrow transplant recipients, we demonstrate that our approach has excellent operating characteristics and performs as well as the only other currently published design for schedule finding studies. We also present arguments for the preference of our non-mixture cure model over the existing model.     

Measuring people's trust

Summary. We measure trust and trustworthiness in British society with a newly designed experiment using real monetary rewards and a sample of the British population. The study also asks the typical survey question that aims to measure trust, showing that it does not predict 'trust' as measured in the experiment. Overall, about 40% of people were willing to trust a stranger in our experiment, and their trust was rewarded half of the time. Analysis of variation in the trust behaviour in our survey suggests that trusting is more likely if people are older, their financial situation is either 'comfortable' or 'difficult' compared with 'doing alright' or 'just getting by', they are a homeowner or they are divorced, separated or never married compared with those who are married or cohabiting. Trustworthiness also is more likely among subjects who are divorced or separated relative to those who are married or cohabiting, and less likely among subjects who perceive their financial situation as 'just getting by' or 'difficult'. We also analyse the effect of attitudes towards risks on trust.     

The additive hazards model with high-dimensional regressors

This paper considers estimation and prediction in the Aalen additive hazards model in the case where the covariate vector is high-dimensional such as gene expression measurements. Some form of dimension reduction of the covariate space is needed to obtain useful statistical analyses. We study the partial least squares regression method. It turns out that it is naturally adapted to this setting via the so-called Krylov sequence. The resulting PLS estimator is shown to be consistent provided that the number of terms included is taken to be equal to the number of relevant components in the regression model. A standard PLS algorithm can also be constructed, but it turns out that the resulting predictor can only be related to the original covariates via time-dependent coefficients. The methods are applied to a breast cancer data set with gene expression recordings and to the well known primary biliary cirrhosis clinical data.     

On pseudo-values for regression analysis in competing risks models

For regression on state and transition probabilities in multi-state models Andersen et al. (Biometrika 90:15–27, 2003) propose a technique based on jackknife pseudo-values. In this article we analyze the pseudo-values suggested for competing risks models and prove some conjectures regarding their asymptotics (Klein and Andersen, Biometrics 61:223–229, 2005). The key is a second order von Mises expansion of the Aalen-Johansen estimator which yields an appropriate representation of the pseudo-values. The method is illustrated with data from a clinical study on total joint replacement. In the application we consider for comparison the estimates obtained with the Fine and Gray approach (J Am Stat Assoc 94:496–509, 1999) and also time-dependent solutions of pseudo-value regression equations.     

Parental characteristics and the schooling progress of the children of immigrant and U.S.-born blacks

In this study, I examine disparities in schooling progress among children born to immigrant and U.S.-born blacks. I find that in one- and two-parent families, children born to black immigrants are less likely to fall behind in school than those born to U.S.-born blacks. In two-parent immigrant families, children born to two immigrant parents have a significant schooling advantage over children born to one immigrant parent. While children born to two immigrant parents in the wealthiest black immigrant families do better in the second generation than in the first, the reverse is observed among children in less wealthy families. These findings contribute in two ways to our understanding of the assimilation processes of children born to black immigrant parents. First, they show that there is a positive association between the number of immigrant parents in a family and children’s schooling performance. Second, they suggest that disparities in the assimilation patterns of the children of black immigrants are a likely product of the interaction between their parental characteristics and the socioeconomic circumstances of their families.     

Childlessness and Psychological Well-Being in Midlife and Old Age: An Examination of Parental Status Effects Across a Range of Outcomes

The study explores and distinguishes links between parental status (childless persons, parents with residential children, and empty nest parents) and a range of psychological well-being outcomes in midlife and old age. Data are from the first wave of the Norwegian Life Course, Ageing and Generation (NorLAG) study (n = 5,189). We separate outcomes into cognitive (life satisfaction and self-esteem) and affective (positive and negative affect, depression, loneliness) components. Parental status has a net effect on cognitive well-being among women, as childless women report significantly lower life satisfaction and self-esteem than both mothers with residential children and empty nest mothers. However, motherhood is inconsequential for affective well-being. Among men, parental status is unrelated to any of the well-being aspects. Parental status effects are not modified by age, marital status, and education. The results demonstrate the importance of investigating the effect of parental status and other objective circumstances on a range of psychological well-being outcomes. Furthermore, the results reviewed and presented indicate somewhat more positive effects of parenthood in the Nordic countries than in the US, highlighting the role of social policies in shaping the impact of parental status on well-being.     

Elementary Preservice Teachers’ and Teacher Educators’ Perceptions of Financial Literacy Education

The authors conducted an online survey of elementary teacher education programs within a large midwestern state to assess preservice teachers’ and teacher educators’ beliefs about and preparedness to teach financial literacy. Very few preservice teachers had meaningful experiences with personal finance in high school, college, or personal decision making. No teacher educators reported ever teaching financial literacy in their higher education roles. Only 13% of teacher educators and 25% of preservice teachers thought that it was very important to teach financial literacy in elementary education. Most teacher education faculty and preservice teachers reported that they were not well qualified to use state economics standards or the JumpStart standards for financial literacy. Preservice teachers were more confident in meeting financial literacy standards than teacher educators. Both preservice teachers and teacher educators expressed openness to collaborating with other faculty members, members of the financial service industry, and parents to teach financial literacy. Follow-up phone interviews affirmed that elementary preservice teachers and teacher educators value social studies education (and financial literacy) less than reading and mathematics education. Qualitative results also suggest that elementary preservice teachers and teacher educators would like more easily accessible resources for teaching financial literacy.     

Generating Dynamic Democratic Discussions: An Analysis of Teaching With U.S. Presidential Debates

Researchers have found that when young people participate in discussions of controversial political issues, they often become more politically engaged and informed (Hess, 2009 Hess, Diana E. (2009). Controversy in the classroom: The democratic power of discussion. New York, NY: Routledge.[Crossref] , [Google Scholar]). Nonetheless, some educators avoid fostering such discussions because they can become heated and distract from academic learning (Hess, 2002 Hess, Diana E. (2002). Discussing controversial public issues in secondary social studies classrooms: Learning from skilled teachers. Theory &; Research in Social Education, 30(1), 10–41.[Taylor &; Francis Online] , [Google Scholar]). Presidential elections, including the highly publicized debates, provide substantial material for discussions of major national and international issues, but no published research has examined how educators can leverage these events to generate productive civic learning experiences. In this article, we analyze data collected in seven high school classrooms during the 2012 presidential election to examine the challenges and opportunities associated with generating substantive, dynamic discussions of presidential debates. Our findings indicate that students enjoyed learning about candidates' different perspectives and that certain strategies were especially helpful for fostering substantive discussions: (a) scaffolding students' preparation for discussion; (b) providing opportunities for students to address open-ended questions; (c) redirecting students' engagement in competitive, interpersonal dynamics to learning about public issues; and (d) countering students' partisan tendencies. We discuss implications for practice and research and present a conceptual framework for generating dynamic, substantive democratic discussions.     

REPEATED LOBBYING BY COMMERCIAL LOBBYISTS AND SPECIAL INTERESTS

Developing a lobbying model of repeated agency, we explain previously unexplained features of the real‐world lobbying industry. Lobbying is divided between direct representation by special interests to policymakers, and indirect representation where special interests employ professional intermediaries called commercial lobbyists to lobby policymakers on their behalf. Our analytical structure allows us to explain several trends in lobbying. For example, using the observation that in the United States over the last 20 years, policymakers have spent an increasing amount of their time fundraising as opposed to legislating, we are able to explain why the share of commercial lobbyist activity in total lobbying has risen dramatically and now constitutes over 60% of the total. The key scarce resource in our analysis is policymakers' time. Policymakers allocate this resource via implicit repeated agency contracts that are used to incent special interests and commercial lobbyists to provide a mix of financial contributions and information on policy proposals. These implicit agency contracts solve both an information problem in the presence of unverifiable policy information and a contracting problem in the absence of legal enforcement. These repeated relationships, that are often described using the pejorative term “cronyism” in the popular press, may in certain circumstances be welfare improving. (JEL D72, D82, H1, P16)