Commitment, Risk, and Consumption: Do Birds of a Feather Have Bigger Nests?

Consumption commitments—goods like housing for which adjustment is costly—change the relationship between risk and consumption. Commitment provides a motive to reduce consumption when possible future losses are too small to warrant adjustment but not when losses are large enough that adjustment would be worthwhile. This implies conditions under which mean-preserving increases in risk can increase housing consumption. Our empirical evidence exploits the interaction of these conditions with a novel proxy for unemployment risk: couples sharing an occupation. Consistent with our model, same-occupation couples consume more housing only when adjustment costs are high and potential losses are sufficiently large

Semiparametric Bayesian Modeling of Income Volatility Heterogeneity

Research on income risk typically treats its proxy—income volatility, the expected magnitude of income changes—as if it were unchanged for an individual over time, the same for everyone at a point in time, or both. In reality, income risk evolves over time, and some people face more of it than others. To model heterogeneity and dynamics in (unobserved) income volatility, we develop a novel semiparametric Bayesian stochastic volatility model. Our Markovian hierarchical Dirichlet process (MHDP) prior augments the recently developed hierarchical Dirichlet process (HDP) prior to accommodate the serial dependence of panel data. We document dynamics and substantial heterogeneity in income volatility

Semiparametric Bayesian Modeling of Income Volatility Heterogeneity

Research on income risk typically treats its proxy—income volatility, the expected magnitude of income changes—as if it were unchanged for an individual over time, the same for everyone at a point in time, or both. In reality, income risk evolves over time, and some people face more of it than others. To model heterogeneity and dynamics in (unobserved) income volatility, we develop a novel semiparametric Bayesian stochastic volatility model. Our Markovian hierarchical Dirichlet process (MHDP) prior augments the recently developed hierarchical Dirichlet process (HDP) prior to accommodate the serial dependence of panel data. We document dynamics and substantial heterogeneity in income volatility

Identifying Idiosyncratic Career Taste and Skill with Income Risk

How important to well-being is choosing a career with the right fit? This question is difficult to answer because we observe individuals only in their chosen careers, not in the other (presumably inferior) options they did not choose. To overcome this problem, we use expected utility to cardinalize a logit model of career choice in a setting where we observe the income risk of chosen careers and the risk-aversion of the people who choose them. The key parameter of interest - the importance of idiosyncratic taste and skill in career choice - is identified from the shift in the distribution of income risk with risk aversion. We estimate the model using individual-specific measures of income volatility to proxy for income risk and survey questions about hypothetical income gambles to proxy for risk preference, both from the PSID. We separate idiosyncratic career taste from skill using the pay gap between high and low-income risk people with high and low risk-aversion

The Environmental Kuznets Curve: Exploring a Fresh Specification

The objective of this paper is primarily methodological. Using a new specification, we reanalyze the data on worldwide environmental quality investigated by Gene Grossman and Alan Krueger in their well-known paper on the environmental Kuznets curve (which postulates an inverse U-shaped relationship between income level and pollution). This new specification avoids using nonlinear transformations of potentially nonstationary regressors in panel estimation, which is a major unresolved econometric problem plaguing much of the existing literature. We furthermore draw conclusions from fixed effects estimation, which had eluded Grossman and Krueger. Our estimation results indicate the presence of an EKC for only six of the fourteen pollutants, whereas Grossman and Krueger find support for all but one pollutan

Examination of psychological risk factors for chronic pain following cardiac surgery: protocol for a prospective observational study

© Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ. INTRODUCTION: Approximately 400 000 Americans and 36 000 Canadians undergo cardiac surgery annually, and up to 56% will develop chronic postsurgical pain (CPSP). The primary aim of this study is to explore the association of pain-related beliefs and gender-based pain expectations on the development of CPSP. Secondary goals are to: (A) explore risk factors for poor functional status and patient-level cost of illness from a societal perspective up to 12 months following cardiac surgery; and (B) determine the impact of CPSP on quality-adjusted life years (QALYs) borne by cardiac surgery, in addition to the incremental cost for one additional QALY gained, among those who develop CPSP compared with those who do not. METHODS AND ANALYSES: In this prospective cohort study, 1250 adults undergoing cardiac surgery, including coronary artery bypass grafting and open-heart procedures, will be recruited over a 3-year period. Putative risk factors for CPSP will be captured prior to surgery, at postoperative day 3 (in hospital) and day 30 (at home). Outcome data will be collected via telephone interview at 6-month and 12-month follow-up. We will employ generalised estimating equations to model the primary (CPSP) and secondary outcomes (function and cost) while adjusting for prespecified model covariates. QALYs will be estimated by converting data from the Short Form-12 (version 2) to a utility score. ETHICS AND DISSEMINATION: This protocol has been approved by the responsible bodies at each of the hospital sites, and study enrolment began May 2015. We will disseminate our results through CardiacPain.Net, a web-based knowledge dissemination platform, presentation at international conferences and publications in scientific journals. TRIAL REGISTRATION NUMBER: NCT01842568

Analysis of In-Vivo LacR-Mediated Gene Repression Based on the Mechanics of DNA Looping

Interactions of E. coli lac repressor (LacR) with a pair of operator sites on the same DNA molecule can lead to the formation of looped nucleoprotein complexes both in vitro and in vivo. As a major paradigm for loop-mediated gene regulation, parameters such as operator affinity and spacing, repressor concentration, and DNA bending induced by specific or non-specific DNA-binding proteins (e.g., HU), have been examined extensively. However, a complete and rigorous model that integrates all of these aspects in a systematic and quantitative treatment of experimental data has not been available. Applying our recent statistical-mechanical theory for DNA looping, we calculated repression as a function of operator spacing (58–156 bp) from first principles and obtained excellent agreement with independent sets of in-vivo data. The results suggest that a linear extended, as opposed to a closed v-shaped, LacR conformation is the dominant form of the tetramer in vivo. Moreover, loop-mediated repression in wild-type E. coli strains is facilitated by decreased DNA rigidity and high levels of flexibility in the LacR tetramer. In contrast, repression data for strains lacking HU gave a near-normal value of the DNA persistence length. These findings underscore the importance of both protein conformation and elasticity in the formation of small DNA loops widely observed in vivo, and demonstrate the utility of quantitatively analyzing gene regulation based on the mechanics of nucleoprotein complexes