The framing of options for retirement: Experimental tests for policy. ESRI WP604, December 2018

We hypothesise and confirm a substantial framing effect in relation to whether people opt for an annuity on retirement. Two laboratory experiments were conducted in collaboration with a national pensions regulator. Individuals demanded a higher annuity rate when pensions were initially conceived of as an accumulated lump sum – a “nest egg” or “pension pot” – than when they were initially conceived of as retirement income. The effect was recorded using both a matching and a choice procedure. Effect sizes implied more than a doubling of demand for annuities at market rates. While mindful of the need for caution in generalising from hypothetical laboratory studies, the findings have potentially strong policy implications. The framing of pension products in marketing materials and disclosures may have substantial effects on financial risks borne in later life

Development of a Hydrogeological Model of the Borrowdale Volcanics at Sellafield

International audienceThis work has arisen out of recent developments within the radioactive waste research programme managed by Her Majesty's Inspectorate of Pollution, UK (HMIP)*, to develop an integrated flow and transport model for the potential deep radioactive waste repository at Sellafield. One of the largest sources of uncertainty in model predictions, is the characterisation of the hydrogeological properties of the underlying strata, in particular, of the Borrowdale Volcanic Group (BVG) within which the repository is to be located. Analysis of the available borehole data (that released by the proponent company, Nirex, by December 1995) for the BVG formation has indicated a dual regime consisting of flow within faults and flow within the matrix (or an equivalent porous medium containing micro-fractures). Significant relationships between permeability, depth and the presence and orientation of faults have been identified; they account for a variation of up to 6 orders of magnitude in mean permeability measurements. This can be explained in part by the effect of the orientation of the current maximum principal stress directions within the BVG: however, it is likely that permeability is also dependent on the existence of fracture families, which cannot be effectively identified from the data currently available. These analyses have enabled considerable insight to be gained into the dominant features of flow within the BVG. The conceptual hydrogeological model derived here will have a significant effect on the outcome and reliability of future radionuclide transport predictions in the Sellafield area

Interventions to increase physical activity in disadvantaged communities: A review of behavioural mechanisms. ESRI Working Paper No. 646 December 2019

Physical inactivity is now a significant driver of health and social inequalities among socioeconomically disadvantaged communities and poses a major challenge to policymakers, worldwide. Although a vast amount of research has focused on designing and evaluating interventions to increase physical activity, there remains little consensus on which interventions are likely to work. In this narrative review, we build on previous reviews by not only examining what interventions tend to work but by trying to understand why certain interventions tend to work, while others do not, through the lens of behavioural science. We present a behavioural framework through which the existing body of physical activity research could be viewed, in order to identify potentially effective mechanisms that would be likely to work in their intended domain. Our analysis finds that while there is evidence that the physical and educational environment matter for increasing levels of physical activity, interventions are more likely to be successful where they involve a social component. We conclude that a behaviourally informed physical activity intervention would thus employ a set of focused educational and socially-mediated behavioural mechanisms, within an appropriate physical environment

Bayesian hierarchical model for the prediction of football results

The problem of modelling football data has become increasingly popular in the last few years and many different models have been proposed with the aim of estimating the characteristics that bring a team to lose or win a game, or to predict the score of a particular match. We propose a Bayesian hierarchical model to fulfil both these aims and test its predictive strength based on data about the Italian Serie A 1991-1992 championship. To overcome the issue of overshrinkage produced by the Bayesian hierarchical model, we specify a more complex mixture model that results in a better fit to the observed data. We test its performance using an example of the Italian Serie A 2007-2008 championship

Motivating social distancing during the Covid-19 pandemic: An online experiment. ESRI Working Paper No. 658 April 2020

Social distancing during the COVID-19 pandemic will save lives. We tested communication strategies to promote social distancing via an online experiment (N = 500) commissioned by Ireland’s Department of Health. A control group saw a current informational poster. Two treatment groups saw similar posters with messages that highlighted: (i) the risk of transmission to identifiable persons vulnerable to COVID-19; (ii) the exponential nature of transmission. We then measured judgements of behaviours previously identified by focus groups as “marginal” (meaning that people were not sure whether they were advisable, such meeting others outdoors, or visiting parents). We recorded intention to undertake behaviours and stated acceptability of behaviours. Our hypotheses, that both treatments would increase participants’ caution about marginal behaviours, were preregistered (i.e. lodged with an international organisation for open science before data collection). Results confirmed the hypotheses. The findings suggest that the thought of infecting vulnerable people or large numbers of people can motivate social distancing. This has implications for communications strategies. The stud

Survival extrapolation using the poly-Weibull model.

Recent studies of (cost-) effectiveness in cardiothoracic transplantation have required estimation of mean survival over the lifetime of the recipients. In order to calculate mean survival, the complete survivor curve is required but is often not fully observed, so that survival extrapolation is necessary. After transplantation, the hazard function is bathtub-shaped, reflecting latent competing risks which operate additively in overlapping time periods. The poly-Weibull distribution is a flexible parametric model that may be used to extrapolate survival and has a natural competing risks interpretation. In addition, treatment effects and subgroups can be modelled separately for each component of risk. We describe the model and develop inference procedures using freely available software. The methods are applied to two problems from cardiothoracic transplantation

Surplus Identification with Non-Linear Returns. ESRI WP522. December 2015

We present evidence from two experiments designed to quantify the impact of cognitive constraints on consumers' ability to identify surpluses. Participants made repeated forced-choice decisions about whether products conferred surpluses, comparing one or two plainly perceptible attributes against displayed prices. Returns to attributes varied in linearity, scale and relative weight. Despite the apparent simplicity of this task, in which participants were incentivised and able to attend fully to all relevant information, surplus identification was surprisingly imprecise and subject to systematic bias. Performance was unaffected by monotonic non-linearities in returns, but non-monotonic non-linearities reduced the likelihood of detecting a surplus. Regardless of the shape of returns, learning was minimal and largely confined to initial exposures. Although product value was objectively determined, participants exhibited biases previously observed in subjective discrete choice, suggesting common cognitive mechanisms. These findings have implications for consumer choice models and for ongoing attempts to account for cognitive constraints in applied microeconomic contexts