Bystander programs contribute to crime prevention by motivating people to intervene in violent situations. Social media allow addressing very specific target groups, and provide valuable information for program evaluation. This paper provides a conceptual framework for conducting benefit–cost analysis of bystander programs and puts a particular focus on the use of social media for program dissemination and data collection. The benefit–cost model treats publicly funded programs as investment projects and calculates the benefit–cost ratio. Program benefit arises from the damages avoided by preventing violent crime. We provide systematic instructions for estimating this benefit. The explained estimation techniques draw on social media data, machine-learning technology, randomized controlled trials and discrete choice experiments. In addition, we introduce a complementary approach with benefits calculated from the public attention generated by the program. To estimate the value of public attention, the approach uses the bid landscaping method, which originates from display advertising. The presented approaches offer the tools to implement a benefit–costs analysis in practice. The growing importance of social media for the dissemination of policy programs requires new evaluation methods. By providing two such methods, this paper contributes to evidence-based decision-making in a growing policy area.

To guide investments in ecosystem-based adaptation (EbA) in developing countries, numerous stated preference valuation studies have been implemented to assess the value of ecosystem services. These studies increasingly use time payments as an alternative to money. There is limited knowledge, however, about how to convert time to money and how the type of payment affects willingness to pay (WTP). In this study, the results of choice experiments using time and money payments are compared in the context of EbA measures in Vietnam. Six, of which five individual-specific, conversion rates are applied. WTP estimates are found to be higher for time payments. Moreover, the type of payment vehicle as well as the conversion rate has substantial effect on mean WTP and WTP distributions. We discuss implications of these results for the conversion of time to money and the use of resulting WTP estimates in cost benefit analyses in developing countries.

The design of a Payment for Environmental Services (PES) scheme that involves setting a ‘pseudo market price’ per unit of environmental service requires the estimation of demand and supply. This paper presents the results of discrete choice experiments aimed at estimating the demand for environmental and social services generated by a wildlife protection PES scheme in two protected areas in Lao PDR. The discrete choice experiments targeted international tourists sampled at Vientiane airport and the urban Lao population sampled in Vientiane City as potential buyers of the environmental and social services provided by the PES scheme. The survey was customised to a developing country context to address diversity in respondents' literacy levels, language limitations of the interviewers, socio-cultural conventions, and limited trust in confidentiality and anonymity of the survey process. The marginal benefits of the environmental services so estimated were used to inform the development of a PES scheme.

This review evaluates evidence on dietary interventions for cancer survivors giving an overview of people's views and preferences for service attributes and provides a narrative review. After cancer, people often want to change their diet and there is a plethora of evidence why dietary optimisation would be beneficial. However, cancer survivors have different preferences about attributes of services including: place, person and communication mode. Randomised control trials have been reviewed to provide a narrative summary of evidence of dietary interventions. Most studies were on survivors of breast cancer, with a few on colorectal, prostate and gynaecological survivors. Telephone interventions were the most frequently reported means of providing advice and dietitians were most likely to communicate advice. Dietary assessment methods used were FFQ, food diaries and 24-h recalls. Dietary interventions were shown to increase intake of fruit and vegetables, dietary fibre, and improve diet quality in some studies but with contradictory findings in others. Telephone advice increased fruit and vegetable intake primarily in women with breast cancer and at some time points in people after colorectal cancer, but findings were inconsistent. Findings from mail interventions were contradictory, although diet quality improved in some studies. Web-based and group sessions had limited benefits. There is some evidence that dietary interventions improve diet quality and some aspects of nutritional intake in cancer survivors. However, due to contradictory findings between studies and cancer sites, short term follow-up and surrogate endpoints it is difficult to decipher the evidence base.

Choice experiments addressing outcome uncertainty (OU) typically reframe continuous probability densities for each risky outcome into two discrete categories, each with a single probability of occurrence. The implications of this simplification for welfare estimation are unknown. This article evaluates the convergent validity of willingness-to-pay (WTP) estimates from a more accurate multiple-outcome treatment of OU, compared to the two-outcome approach. Results for a case study of coastal flood adaptation in Connecticut, United States, suggest that higher-resolution OU treatments increase choice complexity but can provide additional information on risk preferences and WTP. This tradeoff highlights challenges facing the valuation of uncertain outcomes.

Using nationwide survey data, we investigate U.S. meat goat producer preferences and willingness to pay for meat goat breeding stock attributes. Discrete choice experiments were employed, and mixed logit and latent class models were used for analysis. Results showed that producers preferred animals that were highly masculine/feminine, had good structure and soundness, and were of the Boer breed, whereas they preferred fewer animals that were older, of Kiko and Spanish breeds, and priced higher. Significant preference heterogeneity was found among the respondents. Larger-scale producers had greater preference for high masculinity/femininity, good structure and soundness, and Boer bucks.

This paper investigates the structural reliability of a discrete choice experiment within health technology assessment. Two versions of a discrete choice experiment, in the form of a self-completion questionnaire, were randomly administered to two samples of women who had recently given birth as part of an exercise to determine women's preferences for alternative modes of intrapartum care. In the first questionnaire, two of the attributes had only their highest and lowest levels included, while in the second questionnaire all three levels for these two attributes were included. The levels included for all other attributes remained the same throughout both questionnaires. The evidence relating to the structural reliability of the discrete choice experiment in this context was mixed. The results indicated that the relative importance of the two attributes in which the levels were varied increased as the number of levels for these attributes increased. However, the relative importance of the attributes in which the levels were not varied remained relatively stable throughout. The results provide evidence in support of a psychological effect whereby respondents place more importance upon specific attributes as the number of levels for these attributes increases. It is recommended that further research of both a qualitative and quantitative nature should be undertaken to assess the potential importance (or otherwise) of a psychological effect relating to the number of levels chosen for attributes within discrete choice experiments in health technology assessment.