a b s t r a c tNo behavior sits in a vacuum, and one behavior can greatly affect what happens next. We propose a conceptual frame within which a broad range of behavioral spillovers can be accounted for when applying behavioral science to policy challenges. We consider behaviors which take place sequentially and are linked, at a conscious or unconscious level, by some underlying motive. The first behavior leads to another behavior which can either work in the same direction as the first (promoting spillover), or push back against it (permitting or purging spillover). Looking through this conceptual lens at the existing evidence, we find pervasive evidence for all kinds of spillover effects across a variety of fields and domains. As a result, behavioral scientists, especially those seeking to inform policy, should try to capture all the ripples from one behavior to the next when a pebble of intervention is thrown in the pond, and not just at the immediate behavioral splash it makes.

Matteo M. Galizzi Department of Psychological and Behavioural Science, London School of Economics and Political AbstractWe present a lab-field experiment designed to systematically assess the external validity of social preferences elicited in a variety of experimental games. We do this by comparing behavior in the different games with several behaviors elicited in the field and with self-reported behaviors exhibited in the past, using the same sample of participants. Our results show that the experimental social preference games do a poor job explaining both social behaviors in the field and social behaviors from the past. We also include a systematic review and meta-analysis of previous literature on the external validity of social preference games.2

This work aims to provide a systematic and updated survey of original scientific studies on the effect of the introduction of reference pricing (RP) policies in Organisation for Economic Co-operation and Development (OECD) countries. We searched PubMed, EconLit and Web of Knowledge for articles on RP. We reviewed studies that met the inclusion criteria established in the search strategy. From a total of 468 references, we selected the 35 that met all of the inclusion criteria. Some common themes emerged in the literature. The first was that RP was generally associated with a decrease in the prices of the drugs subject to the policy. In particular, price drops seem to have been experienced in virtually every country that implemented a generic RP (GRP) policy. A GRP policy applies only to products with expired patents and generic competition, and clusters drugs according to chemical equivalence (same form and active compound). More significant price decreases were observed in the sub-markets in which drugs were already facing generic competition prior to RP. Price drops varied widely according to the amount of generic competition and industrial strategies: brand-named drugs originally priced above RP values decreased their prices to a greater extent. A second common theme was that both therapeutic RP (TRP) and GRP have been associated with significant and consistent savings in the first years of application. A third general result is that generic market shares significantly increased whenever the firms producing brand-named drugs did not adopt one of the following strategies: lowering prices to RP values; launching new dosages and/or formulations; or marketing substitute drugs still under patent protection. Finally, concerning TRP, although more evidence is needed, studies based on a large number of patient-level observations showed no association between the RP policy and health outcomes.

We conduct an "artefactual" field experiment to incorporate three different risk preferences measures within the Innovation Panel (IP) of the UK Household Longitudinal Survey (UKHLS). We randomly allocate to an experimental module a nationally representative sample of 661 adult respondents to the IP Wave 6 (IP6). These subjects respond to the incentive-compatible tasks by Holt and Laury (2002) (HL), and by Binswanger (1980Binswanger ( , 1981 and Eckel and Grossman (2008) (B-EG), and to the SOEP survey questions by Dohmen et al. (2011) for self-reported willingness to take risks in general (SOEP-G), in finance (SOEP-F), and in health (SOEP-H). One year later (IP7) the same measures are repeated for 413 of these respondents. This design allows us to systematically test, for a UK representative sample, the validity of the three measures along three dimensions. First, we look at cross-validity by testing how responses at one point in time correlate across the three tasks, assuming a Constant Relative Risk Aversion (CRRA) utility function. Second, we look at temporal stability by comparing the responses across IP6 and IP7. Third, we look at external validity by considering a range of risky health and financial behaviors in the UKHLS. We have three main findings. First, concerning cross-validity, we find evidence that the different measures generally correlate and map into each other, although their associations are not perfect. Second, concerning temporal stability, there are significant and positive correlations of the B-EG, HL, and SOEP measures across IP6 and IP7. Finally, we find mixed evidence concerning external validity.

ObjectivesTo explore the extent to which doctor-rating websites are known and used among a sample of respondents from London. To understand the main predictors of what makes people willing to use doctor-rating websites.DesignA cross-sectional study.SettingThe Borough of Hammersmith and Fulham, London, England.Participants200 individuals from the borough.Main outcome measuresThe likelihood of being aware of doctor-rating websites and the intention to use doctor-rating websites.ResultsThe use and awareness of doctor-rating websites are still quite limited. White British subjects, as well as respondents with higher income are less likely to use doctor-rating websites. Aspects of the doctor–patient relationship also play a key role in explaining intention to use the websites. The doctor has both a ‘complementary’ and ‘substitute’ role with respect to Internet information.ConclusionsOnline rating websites can play a major role in supporting patients’ informed decisions on which healthcare providers to seek advice from, thus potentially fostering patients’ choice in healthcare. Subjects who seek and provide feedback on doctor-ranking websites, though, are unlikely to be representative of the overall patients’ pool. In particular, they tend to over-represent opinions from non-White British, medium–low-income patients who are not satisfied with their choice of the healthcare treatments and the level of information provided by their GP. Accounting for differences in the users’ characteristics is important when interpreting results from doctor-rating sites.

We systematically investigate the links between the digit ratio (2D:4D)—a biomarker for prenatal testosterone exposure—and two measures of individual risk taking: (i) risk preferences (RP) over lotteries with real monetary incentives and (ii) self‐reported risk attitude (RA). We find that both the right‐hand and the left‐hand digit ratio are significantly associated with RP: Subjects with lower digit ratios tend to choose riskier lotteries. Neither digit ratio, however, is associated with self‐reported RA.

We look at the links between the Digit Ratio—the ratio of the length of the index finger to the length of the ring finger—for both right and left hands, and giving in a Dictator Game. Unlike previous studies with exclusively Caucasian subjects, we consider a large, ethnically diverse sample. Our main results are as follows. First, for Caucasian subjects we estimate a significant positive regression coefficient for the right hand digit ratio and a significant negative coefficient for its squared measure. These results replicate the findings of Brañas-Garza et al. (2013), who also observe an inverted U-shaped relationship for Caucasian subjects. Second, we are not able to find any significant association of the right hand digit ratio with giving in the Dictator Game for the other main ethnic groups in our sample, nor in the pooled sample. Third, we find no significant association between giving in the Dictator Game and the left hand digit ratio.

A growing stream of literature at the interface between economics and psychology is currently investigating ‘behavioral spillovers’ in (and across) different domains, including health, environmental, and pro-social behaviors. A variety of empirical methods have been used to measure behavioral spillovers to date, from qualitative self-reports to statistical/econometric analyses, from online and lab experiments to field experiments. The aim of this paper is to critically review the main experimental and non-experimental methods to measure behavioral spillovers to date, and to discuss their methodological strengths and weaknesses. A consensus mixed-method approach is then discussed which uses between-subjects randomization and behavioral observations together with qualitative self-reports in a longitudinal design in order to follow up subjects over time. In particular, participants to an experiment are randomly assigned to a treatment group where a behavioral intervention takes place to target behavior 1, or to a control group where behavior 1 takes place absent any behavioral intervention. A behavioral spillover is empirically identified as the effect of the behavioral intervention in the treatment group on a subsequent, not targeted, behavior 2, compared to the corresponding change in behavior 2 in the control group. Unexpected spillovers and additional insights (e.g., drivers, barriers, mechanisms) are elicited through analysis of qualitative data. In the spirit of the pre-analysis plan, a systematic checklist is finally proposed to guide researchers and policy-makers through the main stages and features of the study design in order to rigorously test and identify behavioral spillovers, and to favor transparency, replicability, and meta-analysis of studies.