Information processing strategies and framing effects in developing country choice experiments: results from rice farmers in India

This study explores the effect of various information processing strategies specifically related to attribute nonattendance in stated choice experiments. Our approach includes two forms of stated choice task nonattendance, each derived from separately framed questions asked immediately following the completion of each choice task. We also evaluate a measure of inferred serial nonattendance based on the posterior distributions of random coefficient estimates. We find that choice task nonattendance question framing statistically impacts marginal utility coefficients and, to a lesser degree, willingness‐to‐pay estimates. While direct questions addressing attribute attendance or nonattendance affect these estimates, inferred indicators of serial nonattendance suggest that many attributes are not likely ignored as often as respondents may indicate. Further research is needed to assess inferred versus stated approaches to modeling respondent information processing strategies.     

Stated and Inferred Attribute Attendance Models: A Comparison with Environmental Choice Experiments

There is increasing evidence that respondents to choice experiment surveys do not consider all attributes presented in the choice sets. Not accounting for this ‘attribute non‐attendance’ leads to biased parameter estimates, and hence biased estimates of willingness to pay. Various methods exist to account for non‐attendance in the analysis of choice data, with limited agreement as to which method is ‘best’. This paper compares modelling approaches that can account for non‐attendance, based on stated and inferred attribute non‐attendance. Respondents' stated non‐attendance is incorporated in the specification of multinomial and mixed logit models. Inference of non‐attendance is based on equality constrained latent class models. Results show that model fit is significantly improved when attribute non‐attendance is taken into account, and that welfare estimates are lower when incorporating non‐attendance. The inference based on equality constrained latent class models provides the best model fit. There is little concordance between stated and inferred non‐attendance, suggesting that respondents may not answer attendance statements truthfully.     

Attribute Specific Impacts of Stated Non‐Attendance in Choice Experiments

In this paper, we generalise existing approaches to the treatment of stated attribute non‐attendance data in discrete choice experiments by allowing attribute specific impacts. We implement this approach by employing an extended hierarchical Bayes logit model specification. To illustrate this approach, we consider data collected to examine Indian consumers’ preferences for traditional aromatic rice varieties. Our results regarding stated attribute non‐attendance reveal that, our new approach shrinks marginal utilities of non‐attenders substantially compared to stated attenders, with significant differences in the shrinkage between some of the attributes. In addition, our results reveal the way in which non‐attendance of attributes interact with each other and the impact that this has on the distribution of willingness to pay estimates.     

Comparing Serial,and Choice Task Stated and Inferred Attribute Non‐Attendance Methods in Food Choice Experiments

A number of choice experiment (CE) studies have shown that survey respondents employ heuristics such as attribute non‐attendance (ANA) while evaluating food products. This paper addresses a set of related methodological questions using empirical consumer data from a CE on poultry meat with sustainability labels. First, it assesses whether there are differences in terms of marginal willingness to pay estimates between the two most common ways of collecting stated ANA (serial and choice task level). Second, it validates the self‐reported ANA behaviour across both approaches. Third, it explores the concordance of stated methods with that of the inferred method. Results show that WTP estimates from serial‐level data differ from those from choice task‐level data. Also, self‐reported measures on choice task ANA are found to be more congruent with model estimates than those for serial ANA, as well as with inferred ANA.     

Examining demand for urban river rehabilitation in Indonesia: Insights from a spatially explicit discrete choice experiment

The demand for urban river rehabilitation can be measured through stated preference surveys such as choice experiments, providing information on the welfare estimates of a particular approach. We deploy such a technique in the context of plans to rehabilitate a major river in Jakarta, Indonesia. The current plan focuses on widening and canalizing the downstream segment of the river within Jakarta’s administrative boundary. We hypothesize that residents would demand (and thus be willing to pay for) additional components of an ecological rehabilitation program in the form of riverside park space and upstream forest conservation outside of Jakarta’s jurisdiction. We develop a spatially-explicit discrete choice experiment in which households register their preferences for channel widening, park space, forest conservation, and a monthly fee to fund the rehabilitation. Using mixed logit models we find significant and substantial demand for both park space and forest conservation, with a lower bound on the total willingness to pay (WTP) of greater than US $4 million per year for park space and nearly US $6 million per year to support reforestation in the upper catchment. These estimates are based on households within the catchment, but we find that demand did not seem to decay with distance so the upper bound on total WTP could be substantially higher. We also find that household income level has a strong effect on marginal WTP for forest conservation, minimal effect on marginal WTP for park space, and that location along the river influenced WTP for park space and channel widening. This provides further evidence that there is substantial demand for river rehabilitation in developing world cities, and that choice experiments can provide information relevant to land use planning.     

Modelling outcome‐related risk in choice experiments

In this study, we introduce information on outcome‐related risk as an additional attribute in a choice model of preferences for a land‐based climate change mitigation project. We provide a comprehensive comparison of different model specifications arising from different behavioural assumptions about the way that respondents process information on outcome‐related risk within the choice task. We find significant differences between several specifications in terms of both model fit and WTP estimates. The behavioural assumptions made when choosing a particular model specification, and reasons that motivate them should be made explicit, and consequences of using different specifications should not be ignored.     

Consumer sorting and hedonic valuation of wine attributes: exploiting data from a field experiment

This article uses a novel experimental approach to measure consumer willingness to pay (WTP) for wine attributes. We invited customers of a local supermarket who had selected a bottle of wine to purchase to participate in a valuation experiment. Integrating their original wine choice into the experiment, each participant evaluated six alternative wines, generating a rich set of data on willingness to pay and consumer characteristics. The data from the experiment allow us to compare standard shelf price‐based wine attribute valuation estimates with estimates using WTP data and an increasing amount of information about individual consumers. The full model employs individual fixed effects to estimate WTP parameters without bias from consumer sorting or supply side influences. Our WTP estimates for wine attributes differ markedly from previous attribute value estimates. Consumers in our sample display clear and stable preferences for wine varieties, but less clear preferences for appellations. Our results suggest caution is needed in using market prices to estimate parameters of the consumer valuation function for product attributes.     

Including cost income ratio into utility function as a way of dealing with ‘exploding’ implicit prices in mixed logit models

The estimates of mean WTP are typically of main interest in non-market valuation studies. In the case of mixed logit models the distribution of WTP for an attribute is derived from the distribution of the ratio of individual coefficients. Since the cost coefficient enters the denominator, its distribution plays a major role in the distribution of WTP. A standard practice in analysing the data from choice experiments is to assume the cost coefficient is fixed, which implies that there is no heterogeneity in price sensitivity. The three most commonly given reasons for this are: (i) the distribution of the marginal willingness-to-pay for an attribute is then simply the distribution of that attribute's coefficient; (ii) in this way analysts wish to restrict the price variable to be non-positive for all individuals; and (iii) analysts avoid assuming log-normal cost because it is often found to produce behaviourally implausible estimates. Constraining a price coefficient to be fixed can however have serious consequences, i.e. a constant price coefficient implies that the standard deviations of unobserved utility is the same for all observations which can lead to biased results. Respondents are also likely to vary in price sensitivities, thus ignoring this variation can lead to erroneous interpretation and conclusions. In this paper we demonstrate a choice experiment exercise in which specifying a log-normal cost results in implausibly large WTP, however, adding into the utility function the cost income ratio prevents implicit prices from ‘exploding’.     

A meta-regression analysis on the willingness-to-pay for country-of-origin labelling

Food quality and food safety issues arouse increasing interest and concern among consumers and policy-makers. Consequently, the importance of country-of-origin labelling (COOL) is increasing in business, policy and research. Numerous studies have reported a wide range of estimates for consumers' willingness-to-pay (WTP) for COOL using stated preference methods and, in particular, discrete choice experiments. We apply meta-regression analyses to synthesise the heterogeneous results of 204 WTP for COOL estimates extracted from 59 studies which used discrete choice experiments and were published between 2009 and 2020. Meta-regression analysis allows an adjusted summary proxy to be derived for the WTP for COOL and the determinants of heterogeneity in reported WTP estimates are also investigated. Our results suggest that there is a significant positive WTP for COOL, and also reveal that the reported WTP estimates are unaffected by publication bias. In addition, they show systematic variation in WTP estimates across the context and methodological characteristics of the studies. More precisely, we find that the region and the product (animal- vs. plant-based) analysed, as well as certain characteristics of the choice design (e.g., the number of attributes used, or the inclusion of an opt-out option) can have a significant impact on the estimated WTP for COOL. Finally, our results reveal significant differences in price premiums between various types of COOL (e.g., domestic vs. foreign). This highlights that results from individual primary studies should not be generalised without further consideration of the underlying study design.     

Protester or non‐protester: a binary state? On the use (and non‐use) of latent class models to analyse protesting in economic valuation*

In the analysis of stated preferences studies, it is often assumed that protesting is a discretely measured item only occurring among those who are not willing to pay. However, various studies have recently shown that protest beliefs are as well held by respondents who state a positive willingness to pay (WTP). Using latent class (LC) models, we investigate the extent of heterogeneity with respect to protest beliefs among all respondents of two contingent valuation studies. The advantage of LC models is that classes of individuals are endogenously identified and no selection bias is introduced by ad hoc definitions of protesters. Further we investigate whether it is possible to identify a class of non‐protesters. Finding a group of pure non‐protesters could indicate how strongly stated WTP in the whole sample is affected by protest beliefs. For both samples, we find a class with strong protest beliefs but no pure non‐protest class. Overall, our results suggest that LC models might not be the first choice to determine unbiased WTP measures, but they provide valuable insights into the degree of protesting expressed by different groups and corresponding determinants of group membership.     

Choice of Rice Production Practices in Ghana: A Comparison of Willingness to Pay and Preference Space Estimates

Rice has been identified as an important food security crop in Ghana. However, there is a production deficit and new technologies to reduce the deficit are not widely adopted. Although poor adoption by farmers’ is often linked to constraints such as access to information, farmers’ perceptions of the technologies are also important. We apply an advanced discrete choice experiment to evaluate farmers’ preferences for rice production practices. Specifically, we generate willingness to pay (WTP) estimates using willingness to pay space (WS) and compare these with values from the indirect or preference space (PS) method. Our modelling also accounts for the effects on WTP estimates of farmers’ stated attribute importance (SAI) information. Empirical results from WS and PS models reveal that on average, farmers value higher yields and are negatively affected by higher risk of crop failure and labour requirements. Comparing the performance of the two models, we find the WS model provides a superior fit to our data and reduces the likelihood of producing implausible WTP estimates. Further, SAI inclusion did not produce much variation in our WTP estimates.     

Design Factors Influencing Willingness‐to‐Pay Estimates in the Becker‐DeGroot‐Marschak (BDM) Mechanism and the Non‐hypothetical Choice Experiment: A Case of Biofortified Maize in Zambia

Two of the experimental methods used to estimate willingness‐to‐pay (WTP) for a non‐market good, the Becker‐DeGroot‐Marschak (BDM) mechanism and the non‐hypothetical choice experiment (nHCE) often lead to significantly different WTP estimates, complicating the choice between the methods. In Zambia the same group of researchers used both techniques to evaluate WTP for orange maize, which provides more vitamin A than other varieties. This provided an opportunity to analyse the sources of the difference. In the BDM experiment, one group of respondents was provided with more training opportunities than the other, and made higher bids. Accounting for lexicographic behaviour in the nHCE reduced the estimated WTP. These two design factors together resulted in a decrease in the WTP difference for orange maize (1,279–632 ZMK) although the difference remains statistically significant. More training was also shown to eliminate the effects of different orders in which maize varieties were presented.     

Value elicitation for multiple quantities of a quasi‐public good using open ended choice experiments and uniform price auctions

Choice experiments and experimental auctions have become popular mechanisms for estimating willingness to pay (WTP). However, these methods have primarily been used for estimating WTP for single units of goods. We analyze the results from experimental auctions and choice experiments in the context of multiple quantities of a quasi‐public good (animal welfare product). We show that the use of WTP values for a single unit of a product, a common practice in experimental valuation literature, can result in underestimation of aggregate demand. We use and compare open ended choice experiments (OECE), second price Vickrey auctions, and random Nth price auctions as mechanisms for valuing WTP. Our results also suggest that individual level demand estimates from OECE are less elastic than demand estimates from uniform price auctions.     

The impact of deal‐proneness on WTP estimates in incentive‐aligned value elicitation methods

Even after controlling for hypothetical biases, some incentive‐aligned value elicitation methods still produce different willingness‐to‐pay (WTP) estimates. In this study, we compare WTP estimates from three incentive‐aligned value elicitation methods: real choice experiment (RCE), real double‐bounded dichotomous contingent valuation (RCVM), and Becker–DeGroot–Marschak auction (BDM). We find that participants’ aggressiveness in obtaining low prices (i.e., “deal‐proneness”) influences WTP estimates in the BDM auction, but not those elicited from the RCE and RCVM. The participants with higher levels of deal‐proneness tend to submit lower bids in the BDM auction. The discrepancies in WTP estimates between different incentive‐aligned procedures are narrower for participants with lower levels of deal‐proneness. Our results indicate that the bids in BDM auctions may be understated and the auction mechanism may induce the “gambling behavior” of people who are deal‐prone. That is, whether the BDM auction is truly incentive‐aligned is again called into question. We also discuss the practical implications for food retailers.     

Protest Responses and Willingness to Accept: Ecosystem Services Providers’ Preferences towards Incentive‐Based Schemes

The identification and treatment of protest responses in stated preference surveys has long been subject to debate. We analyse protest responses while investigating ecosystem services providers’ preferences for incentive‐based schemes. We use a choice experiment for olive farmers’ preferences for agri‐environmental scheme participation in southern Spain. Our two main objectives are: first, to identify and discuss a range of possible motives for protest responses that emerge in a WTA context; second, we analyse the impact on WTA estimates of censoring serial non‐participation linked to protest or high compensation requirements (very high takers). Using a random parameter logit model in WTA space, we find that the inclusion or exclusion of serial non‐participants in the analysis can have a significant impact on marginal and total WTA estimates. Based on the findings, the paper makes recommendations on how to reduce the incidence of protest responses through survey design, regarding the identification of protesters as opposed to very high takers, and regarding the treatment of both groups of respondents for WTA estimation.     

Meta-analysis of consumer's willingness-to-pay premiums for certified wood products

Consumers’ willingness to pay (WTP) price premiums for environmentally certified wood products has been frequently estimated using stated preference methods. Estimates of WTP premiums for certified wood products over non-certified options reported in the literature range from 1.0% to 39.3%. This paper describes a meta-analysis used to determine the key factors associated with WTP price premium estimates by examining data from 19 different studies conducted around the world. Results of Bayesian hierarchical models show that frequently purchased wood products and wood products with lower base prices tend to capture higher percentage premiums. Survey administration method was also a statistically significant factor influencing variations in WTP estimates. Results show that conjoint analysis elicited inflated WTP estimates toward certified wood products compared with contingent valuation methods. Reported WTP estimates have increased in recent years. Recommendations to reduce the error of WTP estimates toward certified wood products and improve the validity of experimental studies are provided.     

The Impacts of Elicitation Context on Stated Preferences for Agricultural Landscapes

Statements of willingness to pay (WTP) have been shown to be dependent upon the framing of the hypothetical market. In this paper we investigate the effects of variations in the timing and location of choice experiment questions concerned with conservation of a UK national park, as research involving measurement of psychological well‐being suggests potential differences for the same individual dependent upon when and where preferences are elicited. We apply the choice experiment technique to the valuation of changes in upland agricultural and semi‐natural landscapes in the Peak District National Park in the UK, to investigate whether timing and location of elicitation (context) affects the value associated with changes in ecosystem services under different management regimes. Four treatments are employed – using the same sample of individuals answering the same choice scenarios – to measure WTP ex‐ante (off site), in situ (on site), and ex‐post at two different time intervals (off site). We show that our on‐site (in situ) treatment generates very different estimates of preferences than any of the off‐site treatments. That stated preferences associated with environmental goods are so context dependent may have implications for the use of stated preferences in policy analysis in terms of identifying how environmental policy is funded and the divergence in value attributed to sampling different populations.     

Valuation of ecosystem services provided by irrigated rice agriculture in Thailand: a choice experiment considering attribute nonattendance

This research investigates how the public of a middle‐income country, Thailand, values ecosystem services associated with irrigated rice agriculture using a choice experiment. The results show a significant willingness to pay for services such as drought mitigation, water quality and the environment and maintenance of rural lifestyles and rice landscapes. The iterative procedure developed to fully analyze the incidence of attribute nonattendance (ANA) improved the model fit when compared with a multinomial logit model or an ANA model with potentially only one attribute ignored at a time (ANA‐1). Moreover, the inferred probability of the class of respondents having attended all attributes was 45%, compared to 9% with ANA‐1 model. However, it also suggests that 55% of the respondents made their choices by considering only two of the five attributes. Finally, this research also suggests that failing to consider ANA does not change the public ranking of scenarios contrasted by the services they would provide but would overestimate the WTP for these scenarios.     

Convergent validity in contingent valuation: an application to the willingness to pay for national climate change mitigation targets in Germany

This stated preferences survey determines the willingness to pay (WTP) for climate change mitigation policies using a representative sample of the German population. WTP is compared across three valuation question formats in a split sample design: the dichotomous choice (DC) referendum, the dissonance minimizing (DM) referendum and the two‐way payment ladder (TWPL). The influence of multinational cooperation on WTP is assessed by variation in the hypothetical scenarios. We demonstrate that the DM referendum and the TWPL, two question formats that induce similar response incentives, yield equal mean WTPs. Multinational cooperation did not change WTP in any of the question formats. Implications for current contingent valuation practice are discussed.     

Using Geographically Weighted Choice Models to Account for the Spatial Heterogeneity of Preferences

In this paper, we investigate the use of geographically weighted choice models for modelling spatially clustered preferences. We argue that this is a useful way of generating highly‐detailed spatial maps of willingness to pay for environmental conservation, given the costs of collecting data. The data used in this study come from a discrete choice experiment survey of public preferences for the implementation of a new national forest management and protection programme in Poland. We combine these with high‐resolution spatial data related to local forest characteristics. Using locally estimated discrete choice models we obtain location‐specific estimates of willingness to pay (WTP). Variation in these estimates is explained by characteristics of the forests close to where respondents live. These results are compared with those obtained from a more typical, two stage procedure which uses Bayesian posterior means of the mixed logit model random parameters to calculate location‐specific estimates of WTP. We find that there are indeed strong spatial patterns to the benefits of changes to the management to national forests. People living in areas with more species‐rich forests and those living nearer bigger areas of mixed forests have significantly different WTP values than those living in other locations. This kind of information potentially enables a better distributional analysis of the gains and losses from changes to natural resource management, and better targeting of investments in forest quality.