Conference Agenda

The role that biodiversity plays in impacting fishing yield in freshwater systems is

not well understood. Using detailed data on fish catch and fish diversity from part

of the Mekong River Basin, we take advantage of the natural variation in the

physical environment along the river to show that higher levels of diversity lead to

economically significant increases in freshwater fish yield. Our results are robust

to different methods of measuring diversity, including species and functional

richness, and align well with predictions based on ecological theory. Importantly,

by measuring functional richness, we show that the community is vulnerable to the

extinction of a small number of key species, which, if lost, could compromise the

productivity of local fisheries. Our analysis suggests that win‒win outcomes exist

through protecting biodiversity and thereby enhancing food security in freshwater

fisheries.

If interventions aim to induce a pro-social change in natural resource use, who should they target? To understand whether resource users in leadership positions can facilitate collective change, we study behavior from two nudging experiments with fishermen from the Lake Victoria region in Tanzania. We find that vessel owners and to a lesser extent also captains are receptive to a norm-nudge that aims to induce contributions to a public good. In contrast, the intervention fails with regular crew members. We show that the result is not explained by the fact that resource users in leadership positions are more strongly affected by social information per se but rather that the effect depends on the behavior in question and the recipient of the message. Our study has an important policy implication: to activate pro-social behavior that facilitates sustainable resource use, policy makers may target resource users in leadership positions as ``captains of change".

Land managers rely on fluctuating marketable ecosystem services, which exposes them to income uncertainty. Payments for Ecosystem Services (PES) have gained popularity as a means to incentivize land managers to provide public-good ecosystem services. We study if PES can help insuring against the income risk faced by land managers. We set up an ecological-economic model incorporating interconnected income sources, from marketable ecosystem services and from payments for public-good ecosystem services, which are both uncertain. We show that both action-based and performance-based PES have different insurance functions, the latter depending on the correlation between marketable and public-good ecosystem service provision. We apply the model to data from a large-scale grassland experiment with biomass yield as marketable ecosystem service and soil organic carbon as public-good ecosystem service, both of which are affected by plant biodiversity. We find that both types of PES lead to the adoption of maximum plant biodiversity. Performance-based PES introduce additional income risk, as soil organic carbon and biomass yield are positively correlated, thus resulting in un-insurance.

The single-site travel cost model is a method typically used to estimate the recreational value of open-access natural areas. However, when utilised at sites where multiple ecosystem types are present, the proportion of value that is generated by each ecosystem can be unclear. Natural capital frameworks such as the UN’s System of Economic and Environmental Accounting require values that are ecosystem specific. Therefore, recreational values from single-site travel cost model may be difficult to incorporate. In this study, we value a protected coastal site using single-site travel cost model and demonstrate ways to assign a proportion of the total site value to one of the key ecosystems at the site, saltmarsh. We simultaneously broaden the applicability of travel cost model results and answer the call for more research on the cultural ecosystem services of saltmarsh. The welfare estimate for the entire site is €4.2 million per year. The value that can be attributed to saltmarsh ranges from €223,725 - €1.09 million, depending on the approach used. We discuss the relevance of these approaches for different contexts, including natural capital accounting.

Shifting individual behaviour is an important tool for addressing environmental issues and there is a wide literature evaluating interventions to encourage pro-environmental behaviour. One important but under-researched area is the effect of combining interventions to affect behaviour. In this paper, we evaluate the effects of two interventions – monetary incentives and nudges – on nature restoration volunteering. We use a two-by-two treatment design to evaluate the individual and combined effects of the interventions in a field experiment setting. We find that the monetary incentive significantly increases volunteering behaviour, despite concerns incentives may crowd out motivation, but that nudging alone is ineffective at shifting behaviour. However, there are considerable positive synergies between the monetary incentive and nudge. The monetary incentive becomes more than twice as effective when it is combined with a nudge. We find support for our theoretical prediction that this synergy arises because the nudge reduces motivational crowding out effects from the incentive. Our results have important policy implications, showing that concerns around motivation crowding out from monetary incentives could be mitigated by simple, low-cost nudges.

Over the past two decades, protected areas (PAs) have been the main tool used to conserve biodiversity and prevent its loss. Environmental agreements such as the 2030 Agenda and the Aichi Targets have encouraged an increase in the proportion of marine and terrestrial PAs worldwide. Studies evaluating the impact of PAs have focused on deforestation, poverty, individual species, and vegetation cover using discrete treatment methods. However, research on the effectiveness of PAs and their categories on the biodiversity indices established by the Convention on Biological Diversity (CBD) using continuous treatment is scarce. We assess the impact on the Red List Index (RLI) and Tree Cover Loss (TCL) of the percentage increase in PA relative to the total area of the country using a novel difference-in-differences (DiD) with Heterogenous and continuous treatment method. For these two indices, we found no significant effects of accumulated total protected area. We estimated dynamic effects from 2001 to 2020 for strictly protected areas (IUCN categories I-II), and the seven categories defined by the International Union for Conservation of Nature (IUCN). We found that the average effect on the RLI and tree cover loss of Strictly PAs was not statistically significant. In the eighth period there was a dynamic effect, the risk of species extinction reduced by 0.68 percentage points after 8 years when strict PA increase one percent. Similarly, we found a statistically significant dynamic effect in the 17th period on the reduction of tree cover loss of 1.52 percentage points when category (IV) increases by one percent after 17 years. The use of this novel quasi-experimental method applied in this research to assess the impact of protected areas on biodiversity outcomes contributes to improving the analysis of environmental and conservation programs at regional or country level, and to environmental policy making.

The current food system is one of the main causes of climate change and biodiversity loss, so that appropriate policy measures are needed to mitigate the damages in this sector. Based on data from a broadly representative survey among more than 3,000 citizens in Germany, this paper therefore empirically examines the individual support for various pro-environmental food and agricultural policy measures that are actually discussed in the public and political sphere. The descriptive statistics of our data show a relatively strong support for many measures. In line with previous studies on general climate policy measures, the descriptive analysis also shows that pull policy measures (e.g. tax decreases on plant-based food) tend to receive a higher support than push policy measures (e.g. tax increases on dairy products). Our econometric analysis with multivariate ordered and binary probit models reveals that higher environmental attitudes, i.e. a higher environmental awareness and especially an ecological policy identification, lead to a significantly higher acceptance of these pro-environmental policy measures . In particular, citizens who follow a meat-free diet have a significantly higher level of support for all pro-environmental food and agricultural policy measures . This result could be partly related to individual self-interest (e.g. for the decrease of taxes on plant-based food). In addition, socio-economic variables also play a role. For example, the policy acceptance is mostly significantly higher among females than among non-females . Interestingly, older citizens have a significantly stronger support for policies with an overall high level of acceptance, but a significantly lower support for policies with an overall lower level of acceptance . To test whether information about the damages of the current food system in relation to climate change and biodiversity loss can stimulate the support for corresponding pro-environmental policies, we included a randomized experiment in our survey. The experimental analysis shows that the information about climate change has a significantly positive effect on the support for many policy measures (e.g. the introduction of a “veggieday” in canteens ), whereas the estimated positive effect of biodiversity information is weaker . In contrast, we cannot provide robust evidence for a positive effect of the combined climate and biodiversity information treatment, which could be explained by the negative effect of information overload. Overall, however, we conclude that targeted information-based policy initiatives that highlight the climate damage of the current food system can increase the acceptance of certain pro-environmental food and agricultural policies, at least in the short-run.