Sam Watson’s journal round-up for 9th January 2017

Every Monday our authors provide a round-up of some of the most recently published peer reviewed articles from the field. We don’t cover everything, or even what’s most important – just a few papers that have interested the author. Visit our Resources page for links to more journals or follow the HealthEconBot. If you’d like to write one of our weekly journal round-ups, get in touch.

Non-separable time preferences, novelty consumption and body weight: Theory and evidence from the East German transition to capitalism. Journal of Health Economics [PubMed] [RePEc] Published January 2017

Obesity is an ever growing (excuse the pun) problem associated with numerous health risks including diabetes and hypertension. It was recently reported that eight in ten middle-aged Britons are overweight or exercise too little. A strong correlation between economic development and obesity rates has been widely observed both over time within the same countries and between countries across the world. One potential explanation for this correlation is innovation of novel food products that are often energy dense and of little nutritional benefit. However, exploring this hypothesis is difficult as over the long time horizons associated with changing consumer habits and economic development, a multitude of confounding factors also change. This paper attempts to delve into this question making use of the natural experiment of German reunification in 1989. After the fall of the Berlin Wall a wave of products previously available in West Germany became available to East Germans, almost overnight. The paper provides a nice in depth theoretical model, which is then linked to data and an empirical analysis to provide a comprehensive study of the effect of novel food products in both the short and medium terms. At first glance the effect of reunification on diet habits and weight gain appear fairly substantial both in absolute and relative terms, and these results appear robust and well-founded, theoretically speaking. A question that remains in my mind are whether preferences in this case are endogenous or state dependent, a question that has important implications for policy. Similarly, did reunification reveal East German preferences for fast food and the like, or were those preferences changed as a result of the significant cultural shift? Sadly, this last question is unanswerable, but affects whether we can interpret these results as causal – a thought I shall expand upon in an upcoming blog post.

Ontology, methodological individualism, and the foundations of the social sciences. Journal of Economic Literature [RePEc] Published December 2016

It is not often that we feature philosophically themed papers. But, I am a keen proponent of keeping abreast of advances in our understanding of what exactly it is we are doing day to day. Are we actually producing knowledge of the real world? This review essay discusses the book The Ant Trap by Brian Epstein. Epstein argues that social scientists must get the social ontology right in order to generate knowledge of the social world. A view I think it would be hard to disagree with. But, he argues, economists have not got the social ontology right. In particular, economists are of the belief that social facts are built out of individual people, much like an ant colony is built of ants (hence the title), when in fact a less anthropocentric view should be adopted. In this essay, Robert Sugden argues that Epstein’s arguments against ontological individualism – that social facts are reducible to the actions of individuals – are unconvincing, particularly given Epstein’s apparent lack of insight into what social scientists actually do. Epstein also developed an ontological model for social facts on the basis of work by John Searle, a model which Sugden finds to be overly ambitious and ultimately unsuccessful. There is not enough space here to flesh out any of the arguments, needless to say it is an interesting debate, and one which may or may not make a difference to the methods we use, depending on who you agree with.

Heterogeneity in smokers’ responses to tobacco control policies. Health Economics [PubMedPublished 4th January 2016

In an ideal world, public health policy with regards to drugs and alcohol would be designed to minimise harm. However, it is often the case that policy is concerned with reducing the prevalence of use, rather than harm. Prevalence reducing policies, such as a Pigouvian tax, reduce overall use but only among those with the most elastic demand, who are also likely to be those whose use leads to the least harm. In this light, this study assesses the heterogeneity of tobacco users’ responses to tobacco control policies. Using quantile regression techniques, Erik Nesson finds that the effects of tobacco taxes are most pronounced in those who consume lower numbers of cigarettes, as we might expect. This is certainly not the first study to look at this (e.g. here and here), but reproduction of research findings is an essential part of the scientific process, and this study certainly provides further robust evidence to show that taxes alone may not be the optimum harm reduction strategy.



Sam Watson’s journal round-up for 19th September 2016

Every Monday our authors provide a round-up of some of the most recently published peer reviewed articles from the field. We don’t cover everything, or even what’s most important – just a few papers that have interested the author. Visit our Resources page for links to more journals or follow the HealthEconBot. If you’d like to write one of our weekly journal round-ups, get in touch.

Health losses at the end of life: a Bayesian mixed beta regression approach. Journal of the Royal Statistical Society Series A Published 2nd September 2016

The growth in healthcare expenditure is and has long been a concern for policy makers worldwide. Many factors contribute to this increase, for example it may be a consequence of economic growth, but perhaps the most widely cited determinant is an ageing population. A growing literature is questioning the simplicity of this assumption though: is it age per se that leads to increased healthcare costs or is it proximity to death? This study presents a new analysis of this question. More specifically, the authors propose that the observed decline in health related quality of life (HRQoL) associated with age is due to the increased age-specific mortality and the lower HRQoL associated with being close to death, and not age itself. The implication of this is that increased longevity is unlikely to have a large effect on overall healthcare expenditure. To examine this empirically the authors use longitudinal data on HRQoL from 356 individuals over 16 years. Issues such as the skewness of the outcome measure and it being bounded between zero and one, along with the correlation within individuals over time and the relationship between the mean and variance are accommodated using a Bayesian beta regression. Estimation using MCMC methods provides great flexibility in terms of complex models that may be intractable using classical maximum likelihood methods, and the inclusion of previous evidence through the prior reduces uncertainty that may arise due to smaller sample sizes. A wide range of sensitivity analyses are also conducted. The authors’ key finding is that when time to death is included as a variable the effect of age is almost negligible. This journal round-up author’s interest in Bayesian methods has grown exponentially over the last few years and most of his analyses are now in the Bayesian paradigm. Articles such as this demonstrate the power and flexibility of such methods and, importantly, they show how the emphasis is on the estimation problem rather than arbitrary hypothesis testing and estimation of p-values.

Group-based microfinance for collective empowerment: a systematic review of health impacts. Bulletin of the World Health Organisation Published September 2016

Microfinance initiatives have become a popular method to promote development and a sizable empirical literature has grown around it. Indeed, the 2006 Nobel Peace Prize was awarded to a Bangladeshi microfinance program. Many microfinance schemes are founded on the principle of collective empowerment by providing capital to support female autonomy and entrepreneurship. As such, there is an increasing interest in whether these schemes can also improve health. However, the enthusiasm for microfinance initiatives is often said to outstrip evidence of their effectiveness. This systematic review considers the evidence for whether microfinance can improve health. The studies identified in this review provided evidence that microfinance schemes can reduce maternal and infant mortality, improve sexual health, and in some cases lower interpersonal violence. However, even in the higher quality studies, there was potential for bias and unfortunately publication bias was not assessed. Nevertheless, such a review of the effectiveness of microfinance has been long overdue.

The impact of changing economic conditions on overweight risk among children in California from 2008 to 2012. Journal of Epidemiology and Community Health [PubMedPublished September 2016

The relationship between economic conditions and population health has emerged into a huge research area in the last 20 years. We’ve previously discussed it in a number of blog posts. As the literature grows and understanding and knowledge expand, research moves from generalities to specifics. This article explores whether childhood obesity was affected by changing economic conditions during the last recession using a huge dataset of over 1.7 million children. The proportion of children who are obese is larger among low socioeconomic status groups than higher status groups, so it may be expected that a worsening of economic conditions, measured here as unemployment, would lead to an increase in childhood obesity. However, the authors theorise that the association is ambiguous, citing the typical economic argument that through income and substitution effects households may both change their consumption patterns and the amount of time devoted to health promoting activities, which could either improve or worsen health. Using an individual and county level fixed-effects linear probability model (the justification for using the linear probability model over a perhaps more appropriate nonlinear model is not given), a one percentage point increase (around 10-15% relative increase) in the county level unemployment rate is estimated to lead to a 1.4 percentage point increase in the risk of being obese (around 4% increase in risk). Of course, the results are statistically significant. The results seem reasonable, but I’m left struggling to interpret them properly having had the same issue with an aggregate treatment and individual level outcomes previously. The results are consistent with the idea that the increase in obesity occurred among individuals whose families increased their income over the period, for example. Simpson’s paradox often rears its head in the economic conditions and health literature, as we have previously seen with infant health.

Photo credit: Antony Theobald (CC BY-NC-ND 2.0)

Alastair Canaway’s journal round-up for 12th September 2016

Every Monday our authors provide a round-up of some of the most recently published peer reviewed articles from the field. We don’t cover everything, or even what’s most important – just a few papers that have interested the author. Visit our Resources page for links to more journals or follow the HealthEconBot. If you’d like to write one of our weekly journal round-ups, get in touch.

Question order sensitivity of subjective well-being measures: focus on life satisfaction, self-rated health, and subjective life expectancy in survey instruments. Quality of Life Research [PubMed] Published 30th April 2016

It’s interesting to see an ‘old’ and well known issue rearing its head within the health economics literature. In this case, the focus is on ordering bias within wellbeing questionnaires. It is established within the psychometric and psychological literature that the location of a question within a survey can influence how respondents interpret the meaning of the question, and therefore their answers. This study sought to empirically examine how ordering in subjective well-being measures (life satisfaction, self-rated health, and subjective life expectancy) affected answers. Given ordering bias is an established concept, it wasn’t too surprising to find notable ordering bias depending on how the questionnaire was ordered. For example, as hypothesised by the authors, placing self-rated health immediately before life satisfaction within the survey led to different values compared to when placed apart. For well-being research, the paper has important implications, particularly in how to best order questionnaires to reduce the impact of prior questions on answers, e.g. keeping self-rated health and life satisfaction questions apart to encourage respondents to independently evaluate each question. Ordering bias is one of those issues that most researchers are aware of, but tend to forget about. As much as anything I feel this is for pragmatic reasons, for example, in terms of ease of producing case report forms and also for facilitating data entry within trials. Ideally, we probably should be randomising the order of questionnaires, whether we can persuade wider trial teams that this is necessary remains to be seen.

You sneeze, you lose: The impact of pollen exposure on cognitive performance during high-stakes high school exams. Journal of Health Economics [PubMed] [RePEcPublished September 2016

As a ‘summer sneezer’ and someone with poor exam results in year 9, it was of great interest to read this article. It is known that health and productivity are intrinsically linked, indeed productivity costs related to health are commonly discussed within health economics circles. Elsewhere there are studies that have identified pollution levels as having significant effects on labour productivity and supply. As any fellow hay fever (seasonal allergic rhinitis) sufferers will attest, hay fever has a direct negative impact on wellbeing. Hay fever is relatively prevalent with over one in five people being reported to suffer (in the Norwegian setting at least). This study combined a large administrative dataset from the Norwegian high school system with daily pollen counts from measurement stations across Norway. Student exam data were matched with location of exams and the pollen count for the area in which the exam took place. Fixed effect panel data methods were used to analyse the data. The primary result found that one standard deviation increase in pollen levels led to a decrease in a student’s exam score by about 2.5% of a standard deviation, the implication of this is that for allergic students, this negative effect is approximately 10% of a standard deviation. This is a notable margin. The paper has an interesting discussion on the potential long term impact of hay fever on allergic students, and their future prospects e.g. impact on university enrolment. To avoid such impacts the paper emphasises the need to diagnose early and optimise treatment for hay fever in children. One final point (and word of caution) would be that the methods don’t prove causality, however as a hay fever sufferer, it was very interesting nonetheless to consider how the condition may have impacted upon my own performance at school.

The fatter are happier in Indonesia. Quality of Life Research [PubMed] Published 31st August 2016

An eye-catching title. In developed countries, being overweight and obese typically has negative connotations, and studies repeatedly suggest this is the case: those who are overweight are less happy. In developing countries however, this is not necessarily true. The paper offers the following reason for this: wealth and obesity are positively correlated in such countries, and likewise, happiness and wealth are positively related. Those who are poor in developing countries literally cannot afford to be obese. In contrast, in developed countries, even lower socioeconomic classes can afford to be obese (and obesity is indeed more prevalent in these classes). With this in mind, this study sought to determine how obesity and happiness were related in Indonesia. The study used a large long term survey of over 22,000 participants over a long time period. As hypothesised, the study found there to be a positive association between obesity and self-reported happiness within Indonesia. The paper in a roundabout way suggests that a different approach to evaluating obesity prevention is required in the developing world. I’m not sure this is necessarily the case, in my experience it is rare to assess obesity prevention interventions with respect to ‘happiness’. It takes me back to a previous journal round-up discussing the maximand within economic evaluation. Obesity, if not immediately, eventually is associated with poor health, therefore there is nothing to suggest that an evaluative framework that seeks to maximise health over happiness will not be sufficient. There are many issues related to the long term evaluation of obesity prevention interventions, particularly those focussed in children (as outlined here), however I think the case stated in this paper is a bit of red herring.

Photo credit: Antony Theobald (CC BY-NC-ND 2.0)