A Simple Approach to Fitting Bayesian Survival Models

There has been much recent work on Bayesian approaches to survival analysis, incorporating features such as flexible baseline hazards, time-dependent covariate effects, and random effects. Some of the proposed methods are quite complicated to implement, and we argue that as good or better results can be obtained via simpler methods. In particular, the normal approximation to the log-gamma distribution yields easy and efficient computational methods in the face of simple multivariate normal priors for baseline log-hazards and time-dependent covariate effects. While the basic method applies to piecewise-constant hazards and covariate effects, it is easy to apply importance sampling to consider smoother functions.     

Early origins of the gradient: the relationship between socioeconomic status and infant mortality in the United States

Although relationships between social conditions and health have been documented for centuries, the past few decades have witnessed the emergence of socioeconomic gradients in health and mortality in most developed countries. These gradients indicate that health improves, although decreasingly so, at higher levels of socioeconomic status. To minimize problems with reverse causality, I tested competing hypotheses for observed socioeconomic gradients for infant mortality outcomes. I found no support for the income-inequality hypothesis and negligible support for the occupational-grade hypothesis. The results indicate that absolute material conditions are the most important determinants of socioeconomic effects on the risk of infant mortality and that while poverty has the most pronounced effect on risk, income is decreasingly salutary across the majority of the mortality gradient.     

Specification of objectives in decision problems

If a decision problem is said to be difficult, one usually assumes that there is a very complicated relationship between the decision and the corresponding outcome. The problem is considered as solved when this relationship has been sorted out and described. This means that the probelm of selecting the best outcome from a set of possible outcomes, is taken as trivial. The main, or only difficulty is to find the decision which will lead to the best of the possible outcomes. The author argues that the real difficulty may often be to specify a preference ordering over the set of outcomes. He illustrates the point with examples from economics, and discusses some investment problems, in which the outcome of a decision naturally can be considered as a stochastic process.     

Inequality indices and the starshaped principle of transfers

The evaluation of income distributions is usually based on the Pigou-Dalton (PD) principle which says that a transfer from any people to people who have less decreases economic inequality, i.e., increases the social evaluation index. We introduce two weaker principles of transfers which refer to a parameter θ. With the new principles, only those PD transfers increase the social evaluation index which take from the class of incomes above θ and give to the class below θ. The relative positions of individuals remain unchanged, and either no individual may cross the line θ (principle of transfers about θ) or some may do who have been situated next to it (starshaped principle of transfers at θ). θ may be a given constant, a function of mean income, or a quantile of the income distribution. The classes of indices which are consistent with these transfers are completely characterized, and examples are given.     

Race/Ethnic Differences in Nonspecific Psychological Distress: Evidence from the National Health Interview Survey*

Objective. This article documents the patterns of white‐nonwhite differences in nonspecific psychological distress and explores how acculturation characteristics, social class, marital status, and chronic illness mediate or moderate these differences for eight racial/ethnic populations in the United States. Methods. We analyze data from a five‐year pool of the National Health Interview Survey (NHIS) collected between 1997 and 2001 (N=162,032) and employ multivariate regression techniques to explore level of psychological distress of various ethnic groups relative to non‐Hispanic whites. Results. Nonwhite populations exhibit variable base‐line differences in psychological distress compared to non‐Hispanic whites; however, adjusted estimates show that African Americans and Mexicans have lower levels of distress while distress scores for “other Hispanics,” Asians, and Cubans exhibit statistically similar levels. The highest distress occurs for Puerto Ricans. Interaction models reveal chronic sources of stress (e.g., poverty, chronic illness, nonmarriage) are even more taxing on psychological health of high‐risk groups or have weaker relationships to stress for other groups. Conclusions. This study reveals the need for capturing ethnic variation in studies of mental health. Social class, acculturation, marital status, and chronic illness cannot fully explain white‐nonwhite differences in psychological distress.     

Do Positive Feelings Hurt? Disaggregating Positive and Negative Components of Intergenerational Ambivalence

Ambivalence has become an important conceptual development in the study of parent–adult child relations, with evidence highlighting that intergenerational relationships are characterized by a mix of positive and negative components. Recent studies have shown that ambivalence has detrimental consequences for both parents' and adult children's psychological well‐being. The underlying assumption of this line of research is that psychological distress results from holding simultaneous positive and negative feelings toward a parent or child. The authors question this assumption and explore alternative interpretations by disaggregating the positive and negative dimensions commonly used to create indirect measures of intergenerational ambivalence. Data for the analyses were collected from 254 older mothers and a randomly selected adult child from each of the families. The findings suggest that the negative component is primarily responsible for the association between indirect measures of ambivalence and psychological well‐being. Implications of these findings for the study of intergenerational ambivalence are discussed.     

A new financial risk ratio

Randomness in financial markets has been recognized for over a century: Bachelier (1900), Cowles (1932), Kendall (1953), and Samuelson (1959). Risk thus enters into efficient portfolio design: Fisher (1906), Williams (1936), Working (1948), Markowitz (1952). Reward versus risk decisions then depend upon utility to the investor: Bernoulli (1738), Kelly (1956), Sharpe (1964), and Modigliani (1997). Returns of a portfolio adjusted to risk are measured by a number of ratios: Treynor, Sharpe, Sortino, M2, among others. I will propose a refinement of such ratios. This possibility was mentioned in my recent book: Antieigenvalue analysis, World-Scientific (2011). The result is a new set of growth-to-return risk-based financial ratios of ratios.