Catching Up with the Joneses: Heterogeneous Preferences and the Dynamics of Asset Prices

We analyze a general equilibrium exchange economy with a continuum of agents who have 'catching up with the Joneses' preferences and differ only with respect to the curvature of their utility functions. While individual risk aversion does not change over time, dynamic redistribution of wealth among the agents leads to countercyclical time variation in the Sharpe ratio of stock returns. We show that both the conditional risk premium and the return volatility are negatively related to the level of stock prices, as observed empirically. Therefore, our model exhibits many of the empirically observed properties of aggregate stock returns, e.g., patterns of autocorrelation in returns, the 'leverage effect' in return volatility and long-horizon return predictability. For comparison, otherwise similar representative agent economies with the same type of preferences exhibit counter-factual behavior, e.g., a constant Sharpe ratio of returns and procyclical risk premium and return volatility.

A Multivariate Model of Strategic Asset Allocation

Much recent work has documented evidence for predictability of asset returns. We show how such predictability can affect the portfolio choices of long-lived investors who value wealth not for its own sake but for the consumption their wealth can support. We develop an approximate solution method for the optimal consumption and portfolio choice problem of an infinitely-lived investor with Epstein-Zin utility who faces a set of asset returns described by a vector autoregression in returns and state variables. Empirical estimates in long-run annual and postwar quarterly US data suggest that the predictability of stock returns greatly increases the optimal demand for stocks. The role of nominal bonds in long-term portfolios depends on the importance of real interest rate risk relative to other sources of risk. We extend the analysis to consider long-term inflation-indexed bonds and find that these bonds greatly increase the utility of conservative investors, who should hold large positions when they are available.

A Multivariate Model of Strategic Asset Allocation

We develop an approximate solution method for the optimal consumption and portfolio choice problem of an infinitely long-lived investor with Epstein–Zin utility who faces a set of asset returns described by a vector autoregression in returns and state variables. Empirical estimates in long-run annual and post-war quarterly U.S. data suggest that the predictability of stock returns greatly increases the optimal demand for stocks. The role of nominal bonds in long-term portfolios depends on the importance of real interest rate risk relative to other sources of risk. Long-term inflation-indexed bonds greatly increase the utility of conservative investors.Economic

Cosmic Microwave Background constraints of decaying dark matter particle properties

If a component of cosmological dark matter is made up of massive particles - such as sterile neutrinos - that decay with cosmological lifetime to emit photons, the reionization history of the universe would be affected, and cosmic microwave background anisotropies can be used to constrain such a decaying particle model of dark matter. The optical depth depends rather sensitively on the decaying dark matter particle mass m_{dm}, lifetime tau_{dm}, and the mass fraction of cold dark matter f that they account for in this model. Assuming that there are no other sources of reionization and using the WMAP 7-year data, we find that 250 eV < m_{dm} < 1 MeV, whereas 2.23*10^3 yr < tau_{dm} < 1.23*10^18 yr. The best fit values for m_{dm} and tau_{dm}/f are 17.3 keV and 2.03*10^16 yr respectively.Comment: 17 pages, 3 figure

PAX-D:study protocol for a randomised placebo-controlled trial evaluating the efficacy and mechanism of pramipexole as add-on treatment for people with treatment resistant depression

Introduction: Clinical depression is usually treated in primary care with psychological therapies and antidepressant medication. However, when patients do not respond to at least two or more antidepressants within a depressive episode, they are considered to have treatment resistant depression (TRD). Previous small randomised controlled trials suggested that pramipexole, a dopamine D2/3 receptor agonist, may be effective for treating patients with unipolar and bipolar depression as it is known to influence motivational drive and reward processing. PAX-D will compare the effects of pramipexole versus placebo when added to current antidepressant medication for people with TRD. Additionally, PAX-D will investigate the mechanistic effect of pramipexole on reward sensitivity using a probabilistic decision-making task. Methods and analysis: PAX-D will assess effectiveness in the short- term (during the first 12 weeks) and in the longer-term (48 weeks) in patients with TRD from the UK. The primary outcome will be change in self-reported depressive symptoms from baseline to Week 12 post-randomisation measured using the QIDS-SR. Performance on the decision-making task will be measured at Week 0, Week 2, and Week 12. Secondary outcomes include anhedonia, anxiety, and health economic measures including quality of life, capability, wellbeing, and costs. PAX-D will also assess the adverse effects of pramipexole including impulse control difficulties. Discussion: Pramipexole is a promising augmentation agent for treatment resistant depression and may be a useful addition to existing treatment regimes. PAX-D will assess its effectiveness and test for a potential mechanism of action in patients with treatment resistant depression

The impact of personalisation on people from Chinese backgrounds: accounts of social care experience

The limited research that considers people from black and minority ethnic communities experiences of personalisation tends to focus on personal budgets rather than personalisation per se. This article provides an opportunity to hear the voices of people from Chinese backgrounds and their experiences of personalisation. The study used individual semi-structured interviews and focus groups to collect data from people from Chinese backgrounds who lived in England, were aged between 18 and 70 and received social care for a physical disability. Data were analysed using an iterative and thematic approach, with early analysis informing the subsequent analytical rounds. The findings reveal that personalisation has the potential to transform the lives of people from Chinese backgrounds, especially when tailored support is available for people to understand and access personal budgets and put them to creative use. However, the impact of personalisation is barely evident because few eligible individuals access personal budgets or participate in co-production. This is related to a lack of encouragement for service users to become genuine partners in understanding, designing, commissioning and accessing a diverse range of social care services to meet their cultural and social care needs

Assessment of public health impact of work-related asthma

<p>Abstract</p> <p>Background</p> <p>Asthma is among the most common chronic diseases in working-aged populations and occupational exposures are important causal agents. Our aims were to evaluate the best methods to assess occurrence, public health impact, and burden to society related to occupational or work-related asthma and to achieve comparable estimates for different populations.</p> <p>Methods</p> <p>We addressed three central questions: <b>1: What is the best method to assess the occurrence of occupational asthma? </b>We evaluated: 1) assessment of the occurrence of occupational asthma <it>per se</it>, and 2) assessment of adult-onset asthma and the population attributable fractions due to specific occupational exposures. <b>2: What are the best methods to assess public health impact and burden to society related to occupational or work-related asthma? </b>We evaluated methods based on assessment of excess burden of disease due to specific occupational exposures. <b>3: How to achieve comparable estimates for different populations? </b>We evaluated comparability of estimates of occurrence and burden attributable to occupational asthma based on different methods.</p> <p>Results</p> <p>Assessment of the occurrence of occupational asthma <it>per se </it>can be used in countries with good coverage of the identification system for occupational asthma, i.e. countries with well-functioning occupational health services. Assessment based on adult-onset asthma and population attributable fractions due to specific occupational exposures is a good approach to estimate the occurrence of occupational asthma at the population level. For assessment of public health impact from work-related asthma we recommend assessing excess burden of disease due to specific occupational exposures, including excess incidence of asthma complemented by an assessment of disability from it. International comparability of estimates can be best achieved by methods based on population attributable fractions.</p> <p>Conclusions</p> <p>Public health impact assessment for occupational asthma is central in prevention and health policy planning and could be improved by purposeful development of methods for assessing health benefits from preventive actions. Registry-based methods are suitable for evaluating time-trends of occurrence at a given population but for international comparisons they face serious limitations. Assessment of excess burden of disease due to specific occupational exposure is a useful measure, when there is valid information on population exposure and attributable fractions.</p

Obstetric professionals’ perceptions of non-invasive prenatal testing for Down syndrome: clinical usefulness compared with existing tests and ethical implications

Background: While non-invasive prenatal testing (NIPT) for fetal aneuploidy is commercially available in many countries, little is known about how obstetric professionals in non-Western populations perceive the clinical usefulness of NIPT in comparison with existing first-trimester combined screening (FTS) for Down syndrome (DS) or invasive prenatal diagnosis (IPD), or perceptions of their ethical concerns arising from the use of NIPT. Methods: A cross-sectional survey among 327 obstetric professionals (237 midwives, 90 obstetricians) in Hong Kong. Results: Compared to FTS, NIPT was believed to: provide more psychological benefits and enable earlier consideration of termination of pregnancy. Compared to IPD, NIPT was believed to: provide less psychological stress for high-risk women and more psychological assurance for low-risk women, and offer an advantage to detect chromosomal abnormalities earlier. Significant differences in perceived clinical usefulness were found by profession and healthcare sector: (1) obstetricians reported more certain views towards the usefulness of NIPT than midwives and (2) professionals in the public sector perceived less usefulness of NIPT than the private sector. Beliefs about earlier detection of DS using NIPT were associated with ethical concerns about increasing abortion. Participants believing that NIPT provided psychological assurance among low-risk women were less likely to be concerned about ethical issues relating to informed decision-making and pre-test consultation for NIPT. Conclusions: Our findings suggest the need for political debate initially on how to ensure pregnant women accessing public services are informed about commercially available more advanced technology, but also on the potential implementation of NIPT within public services to improve access and equity to DS screening services

Five Glutathione S-Transferase Gene Variants in 23,452 Cases of Lung Cancer and 30,397 Controls: Meta-Analysis of 130 Studies

BACKGROUND: Glutathione S-transferases (GSTs) are known to abolish or reduce the activities of intracellular enzymes that help detoxify environmental carcinogens, such as those found in tobacco smoke. It has been suggested that polymorphisms in the GST genes are risk factors for lung cancer, but a large number of studies have reported apparently conflicting results. METHODS AND FINDINGS: Literature-based meta-analysis was supplemented by tabular data from investigators of all relevant studies of five GST polymorphisms ( GSTM1 null, GSTT1 null, I105V, and A114V polymorphisms in the GSTP1 genes, and GSTM3 intron 6 polymorphism) available before August, 2005, with investigation of potential sources of heterogeneity. Included in the present meta-analysis were 130 studies, involving a total of 23,452 lung cancer cases and 30,397 controls. In a combined analysis, the relative risks for lung cancer of the GSTM1 null and GSTT1 null polymorphisms were 1.18 (95% confidence interval [CI]: 1.14–1.23) and 1.09 (95% CI: 1.02–1.16), respectively, but in the larger studies they were only 1.04 (95% CI: 0.95–1.14) and 0.99 (95% CI: 0.86–1.11), respectively. In addition to size of study, ethnic background was a significant source of heterogeneity among studies of the GSTM1 null genotype, with possibly weaker associations in studies of individuals of European continental ancestry. Combined analyses of studies of the 105V, 114V, and GSTM3*B variants showed no significant overall associations with lung cancer, yielding per-allele relative risks of 1.04 (95% CI: 0.99–1.09), 1.15 (95% CI: 0.95–1.39), and 1.05 (95% CI: 0.89–1.23), respectively. CONCLUSIONS: The risk of lung cancer is not strongly associated with the I105V and A114V polymorphisms in the GSTP1 gene or with GSTM3 intron 6 polymorphism. Given the non-significant associations in the larger studies, the relevance of the weakly positive overall associations with the GSTM1 null and the GSTT1 null polymorphisms is uncertain. As lung cancer has important environmental causes, understanding any genetic contribution to it in general populations will require the conduct of particularly large and comprehensive studies