National defence is a quintessential public good which generates welfare but does not have a market price to be used for its valuation. This study uses non-market valuation, namely a discrete choice experiment, to enhance the understanding of how individuals' perceptions of threat influence their valuation of defence policy instruments. The analysis employs an integrated choice and latent variable model in which perceptions of foreign, domestic and economic threats are included as latent variables and interacted with estimates of marginal willingness to pay (WTP) for the different policy instruments. Results show that perceptions of foreign threat are associated with higher WTP for defence policy instruments. Effect sizes are substantial, with WTP varying by a factor of 2 to 4 between respondents with the weakest and strongest threat perceptions. In contrast, a strong perception of domestic threats correlates with low or even zero WTP for defence policy instruments. No clear effect can be found for perceived economic threats. The validity of the assessment of threat perceptions is supported by the analysis of systematic variation of threat perception with demographic characteristics. The policy relevance of this link between psychological antecedents and valuation of national defence is discussed.

Private gardens can be an important complement to traditional approaches to biodiversity conservation. While neighbourhood norms are often seen as a barrier to conservation gardening, little is known about individuals’ expectations regarding their neighbouring gardens. Based on a multifactorial vignette experiment and a neighbourhood choice question, our results reveal that existing norms constrain gardening much less than is assumed, leaving significant scope for activating the biodiversity potential of private gardens.

This study introduces the basket-based choice experiment (BBCE) as suggested by Caputo and Lusk (2022) into the field of environmental economics and management. The application is a survey to assess garden owners’ preferences for installing design elements conducive to biodiversity conservation in private gardens. In addition to showcasing this approach in the context of environmental management, the present application of the BBCE adds two new methodological features to this approach. First, an experimental design is used to provide context attributes for each basket-based choice task to assess the extent to which policy levers set by local councils can affect how garden owners design their gardens. Second, the econometric model to analyse the resulting basket-based choice data is augmented by a latent class structure to accommodate the empirical finding that a substantial share of respondents never chose to add any new element to their gardens (i.e. chose an empty basket). Results show that the policy instruments have mixed effects on the element-specific choice probabilities, with financial support for new garden elements exhibiting the strongest effect on demand. Furthermore, it is demonstrated how prediction can be used to assess the uptake of biodiversity friendly garden elements as a function of policy instruments.

National Energy and Climate Plans (NECPs) are the primary roadmaps for European Union countries to achieve their 2030 targets for energy and climate, guiding investment decisions and a significant economic transformation. We conduct a discrete choice experiment to analyze preferences for different energy sources in Italy. We examine preferences regarding various attributes: the capacity shares of the most significant current and projected energy sources, the reliability of the supply of electricity, and cost. We use a latent class model to estimate the willingness to pay (WTP) for each attribute, finding that these preferences can be categorized into four groups. On average, we find overall support for the major renewable energy sources, opposition to fossil fuels and service interruptions, and strong opposition to nuclear power. Based on these results, we calculate the consumer surplus associated with the implementation of the national plan. The results show that the WTP aggregated over Italian households is lower than the investment levels estimated in the NECP. Spreading out the investments envisaged in the NECP over time can bring costs and benefits into better balance.

Forests across Europe are undergoing rapid transformation as biodiversity loss and climate change reshape priorities for forest management. Strategies that promote biodiverse and structurally complex forests are increasingly advocated to enhance ecological resilience, yet they are often assumed to conflict with societal preferences, potentially limiting public support for conservation and restoration. We examined whether forest characteristics associated with biodiversity conservation and climate adaptation are consistently valued by society across Europe. We combined a visual discrete choice experiment involving 11,622 respondents from twelve European countries with a travel cost model to evaluate whether stated societal preferences were reflected in observed recreational behaviour. We then integrated harmonized preference estimates with continental forest inventory and remote-sensing data to map the spatial distribution of societal values associated with forest ecosystem condition. Across all countries, respondents consistently preferred forests characterized by taller canopies, greater tree-species richness, heterogeneous age structures, and more deadwood. These preferences closely aligned with observed visitation behaviour despite substantial differences in geography, accessibility, and recreational traditions. Spatial analyses further showed that forests with greater structural complexity consistently exhibited higher societal value. Our findings demonstrate that biodiversity-oriented forest management and societal values largely converge across Europe, suggesting that many interventions promoting ecological resilience can simultaneously strengthen public support for forest conservation and restoration, providing a stronger foundation for adaptive, multifunctional forest governance under global environmental change.

Distributive justice is an important but often overlooked factor in policy evaluation. We thus examine how people's attitudes towards distributive justice affect their preferences for programmes aimed at reducing ambient air pollution resulting from the combustion of fossil fuels for residential heating. To do so, we carried out two multifactorial survey experiments that allowed us to incorporate justice attitudes into non-market valuation. The first experiment focused on recording justice attitudes towards payment distribution for air quality improvement, while the second experiment measured the willingness to pay for air pollution reduction programmes. Both experiments were conducted with the same respondents, from four cities in Poland, and were conducted separately one to two weeks apart. As a modelling approach, we employ a hybrid choice model. Our findings indicate that people strongly support an equity-based cost distribution and that those with a stronger equity-based distributive justice attitude are more willing to pay for air quality improvement programmes.

Because of the environmental and social benefits associated with urban greening, many cities around the world are implementing strategies to increase tree canopy cover, including along residential streets. However, procedures for developing and implementing these strategies do not always factor in public preferences, which can limit public acceptance. This paper explores public preferences for different characteristics of street trees. Where past studies have relied on capturing perceptions of street trees using rating scales for relatively few attributes, we apply best-worst scaling, which is a type of choice experiment, to assess preferences for 16 different tree characteristics. As the method requires trade-offs from respondents, it results in a systematic ranking of the tree characteristics considered, which represent different ecosystem services, physical attributes, and management requirements. We find that capacity to support local biodiversity and drought tolerance are the two characteristics that are most preferred. We also find that having visual appeal, requiring little maintenance, and having native origins are viewed favourably. Tree characteristics seen as less important include the size and growth rate of a tree, along with whether it holds cultural significance. Better understanding preferences for tree characteristics presents an opportunity for environmental managers to integrate tree species with more widely accepted attributes into urban greening programs.

Various policy interventions can be implemented to motivate individuals to adopt pro-environmental landscaping behaviors. Here we compare the influence of economic incentives and social norms on urban landowners'adoption of native gardens. First, we model the relationship between social norms and landowners' actual land use decisions. We estimate adoption intention under different support programs with a choice experiment, also considering social norms. We find that social norms can play a significant role in the adoption of native gardens, comparable to relatively expensive financial incentives. Therefore, social norms may enhance the performance of incentives to increase rates of land conservation. (JEL Q51, Q58)

Nearly all discrete choice experiments in environmental valuation have a cost attribute to estimate willingness to pay for the goods and services in question. The composition of the cost vector has received little attention in the literature. This paper focuses on whether or not the cost vector should include "prominent amounts" (e.g., $1, $2, $5, $10, $20, $50). On the one hand, these amounts are familiar to participants as they are used in everyday life (e.g., coins or banknotes). On the other hand, respondents may not consider the amounts to reflect the cost of environmental programs, affecting credibility. In a review of published discrete choice experiment articles on wind energy, we find little information on how the levels of the cost attribute vectors were chosen and why prominent amounts are (not) included, reflecting the lack of guidance in the literature. In a split-sample survey on renewable energy, we find that the composition of the cost vector does not affect choice frequencies or the perceived difficulty of the task. However, we observe that the cost vector impacts credibility, suggesting that it may impact the validity of the welfare estimates.

The magnitude and range of the cost attribute levels in stated choice experiments have been found to affect willingness to pay (WTP). Such cost-vector effects are of concern for the validity of derived welfare estimates. This study employs a treatment design to investigate whether a cheap talk and opt-out reminder device mitigates cost-vector effects. In a stated choice experiment to value outcomes of marine management in Germany, results show considerable cost-vector effects when the device is not applied. However, cost-vector effects are reduced substantially in another treatment arm where the combined cheap talk and opt-out reminder device is used. Ancillary results demonstrate how the device increases the validity of stated preference responses and resulting welfare measures. The findings suggest that the inexpensive use of this device in stated choice experiments may be an effective way to mitigate potential cost-vector effects at the design stage.

Adapting to changes in water availability is becoming an increasingly important environmental management objective in many regions around the world. One way for cities to conserve water is to enhance drought-resistant vegetation cover. This revegetation practice can take place on many types of land, including road-side verges (also known as nature strips or boulevards), which, in Western Australia, are publicly owned but managed privately by residents of adjoining properties. As preferences for alternative verge groundcovers are not well understood, designing solutions that help achieve environmental goals and satisfy communities is a challenge. We survey community members in Perth, Western Australia, and find that peoples’ preferences for verge landscape design are largely bimodal, and can be classified under two dominant groups of people: those who prefer native vegetation, which requires little irrigation, and those who prefer watered grass. Neighbourhood norms prevail in their rankings, where individuals whose neighbours have planted water-conserving native vegetation gardens on their verges are also more likely to prefer ecological landscape designs. Increasing the extent of gardens that feature water-conserving native plants in high-profile public areas may further increase community acceptance of low water-use groundcovers, and may assist in driving changes in landscape management practices towards having more ecological landscape designs on verges, and beyond.

This study examines the use of hybrid choice models (HCM), also referred to as integrated choice and latent variable (ICLV) models, within environmental valuation studies. The investigation is motivated by the fact that stated preference surveys in this field increasingly incorporate additional data into their modelling, particularly respondents' attitudes towards the environment in a broader context or specifically towards the environmental changes under evaluation. Key findings include the fact that sample sizes are usually too small for such complex models, that many studies use ad hoc scales as indicators of latent variables without first testing the validity and reliability of the scales, and that model results are often not compared with a benchmark model. One particularly notable finding of the simulation study is that excluding a latent variable, such as estimating Random Parameter Logit (RPL) instead of HCM, does not necessarily lead to biased willingness to pay (WTP) estimates. Therefore, if the inclusion of a latent construct is not critical to the study, we suggest opting for more traditional and robust models such as RPL or Latent Class Models (LCM). The perceived benefits of gaining a better understanding of how latent factors influence decisions come with risks associated with defining and estimating an HCM. To improve the quality of research, we provide recommendations for future applications of HCM in environmental economics.

Defense spending accounts for a large share of the budget in many countries, but the value of the resulting public good - national defense - has so far escaped assessment. Much of the literature has instead considered indirect benefits of defense spending in terms of greater economic growth or technological spillovers. In this paper, we assess the direct welfare effects of defense policy, namely an increase in the security of citizens, by means of a survey-based discrete choice experiment. Drawing on a representative sample of the German population, results suggest substantial willingness to pay for an increase in troop numbers, the establishment of a European army and an improved air defense system. The reintroduction of compulsory military service does not enjoy public support. Results further indicate substantial preference heterogeneity across respondents and policy options which we explore. As such, these findings demonstrate how methods of survey-based, non-market valuation can help to refine research in this area of public policy.

Carbon capture and storage is crucial to achieve net-zero targets and cross-border CO2 transport is essential for cost-efficiency of a carbon capture and storage strategy but how the public views this is unclear. Here, using multifactorial vignette experiments in four European countries and Canada, we show that cross-border transport hinders public acceptance of carbon capture and storage. Public concerns are unlikely to be offset by compensation, presenting a challenge for policy-makers. Carbon removal using carbon capture and storage (CCS) remains controversial. This study finds that cross-border CO2 transport would hinder public acceptance of CCS, associated with the perceived unfairness.

Efficient experimental designs aim to maximise the information obtained from stated choice data to estimate discrete choice models' parameters statistically efficiently. Almost without exception efficient experimental designs assume that decision-makers use a Random Utility Maximisation (RUM) decision rule. When using such designs, researchers (implicitly) assume that the decision rule used to generate the design has no impact on respondents' choice behaviour. This study investigates whether the decision rule assumption underlying an experimental design affects respondents' choice behaviour. We use four stated choice experiments on coastal adaptation to climate change: Two are based on experimental designs optimised for utility maximisation and two are based on experimental designs optimised for a mixture of RUM and Random Regret Minimisation (RRM). Generally, we find that respondents place value on adaptation measures (e.g., dykes and beach nourishments). We evaluate the models' fits and investigate whether some choice tasks particularly invoke RUM or RRM decision rules. For the latter, we develop a new sampling-based approach that avoids the confounding between preference and decision rule heterogeneity. We find no evidence that RUM-optimised designs invoke RUM-consistent choice behaviour. However, we find a relationship between some of the attributes and decision rules, and compelling evidence that some choice tasks invoke RUM consistent behaviour while others invoke RRM consistent behaviour. This implies that respondents’ choice behaviour and choice modelling outcomes are not exogenous to the choice tasks, which can be particularly critical when information on preferences is used to inform actual decision-making on a sensitive issue of common interest as climate change.

This paper connects the concept of involvement with recreational fishing and decision rules, namely regret-minimizing vs. utility-maximizing when making choices related to the activity. We hypothesized that people who are more involved show regret-minimizing rather than utility-maximizing behavior. In support, we found that behavioral commitment, measured as avidity in fishing, and psychological involvement (measured by centrality of angling in the lifestyle of the respondent) was significantly related to the decision rule, correlating with regret-minimizing behavior, while skill, specific attitudes toward the catch and place attachment were unrelated to the decision rules that respondents followed. In our sample, regret-minimizers were dominant and preferred more restrictive harvest policies (i.e., lower daily bag limits or harvest slots over minimum-size limits). Welfare estimates of policy changes were sensitive to the decision rule and were substantially lower when assuming regret minimizing behavior than when assuming utility maximization. We conclude that regret-minimizing behavior may be a characteristic of more involved anglers, with relevant implications for welfare estimation and derivation of policy advice.

Forests are vital for outdoor recreation, benefiting mental, physical, and social well-being. While the importance of forest structure in supporting biodiversity and material ecosystem functions is well-documented, research on its relationship with non-material contributions to people remains limited, and there is a lack of robust indicators for this relationship. Our study addresses this gap by estimating the economic value of recreational benefits provided by forests and quantifying the link between forest complexity and the non-material benefits forests provide. We conducted a large-scale preference survey across 12 European countries (Austria, Belarus, Bulgaria, Czechia, Denmark, France, Germany, Poland, Romania, Scotland, Slovakia, and Switzerland), involving 11,622 respondents. Our findings reveal significant positive correlations between forest complexity and benefits from forest visits. Preferences for older stands with diverse tree species and greater structural complexity were strongly evident across all surveyed countries. Moreover, forests with more complex structures were associated with higher annual visitation frequencies, highlighting the importance of forest quality in driving people’s exposure to nature.

We propose a simple diagnostic check for face validity assessment of willingness to pay (WTP) estimates derived from choice experiments (CEs). The check is based on a threshold value for WTP that is related to the highest cost attribute level, which can be used to assess plausibility of estimated WTP. If the threshold value is exceeded, WTP estimates are considered to overshoot. This may be due to issues with (i) the design of the CE and/or (ii) respondents' behavior deviating from assumptions underpinning CEs. Applying the check to a sample of publications, this paper provides evidence on the incidence and magnitude of overshooting of WTP in the agricultural and environmental CE literature. Based on a random sample of publications including 304 observations representing individual studies and population samples, the results show that overshooting of WTP is widespread, with 65% of observations exceeding the overshooting threshold value. An exploratory analysis to identify factors associated with overshooting of WTP across studies reveals that study design factors, and in particular the design of the cost attribute, play an important role. We recommend that researchers apply the diagnostic check for the design of choice experiments and to motivate further scrutiny of choice experiment results.