David J. Pannell

Research on adoption of new practices, technologies and systems in agriculture has generated thousands of publications over the past 70 years, covering uptake of agricultural practices spanning more than 100 years. This paper contains selected key lessons from the results of this enormous research effort, drawn from numerous reviews of the literature and shaped by personal experience. The lessons include that trialling is not adoption, that extension is not necessarily the key to increasing adoption, that each new farming practice has its own adoption story, and that adoption is often slower than practice advocates expect, typically taking multiple decades. The identified lessons are juxtaposed with a number of flawed assumptions and misconceptions commonly held by people working in agricultural agencies. A number of methodological weaknesses are still common in existing studies, including neglect or poor representation of key variables, compromising the potential for the research to generate real understanding of adoption. This also inhibits comparison of studies and the application of meta‐analyses. Suggestions are made on ways to add value to the existing research and improve the quality of future research, including the collection and curation of good‐quality adoption data sets, the development of a searchable database of adoption studies, and the creation of best‐practice guidelines for the conduct of adoption research.

In analysing potential policy responses to improve outcomes in collective-action problems, economists often focus on financial disincentives to reduce the expected gains from free-riding and thereby promote within-group cooperation. In this study, we investigate the potential for groups to develop non-financial disincentives to free riding, thereby promoting convergence towards collectively beneficial actions. Using a within-subjects laboratory experiment, participants play two multi-period public goods games sequentially: without and then with non-financial incentives activated by allowing for the endogenous formation of a social exclusion mechanism. Participants can choose to bear a personal cost to allow them to assign exclusion tickets to other participants whose contributions to the public good they judge negatively. The member(s) who accumulate the most tickets are excluded from a group activity that involves no monetary payoffs and is not linked to the main game. We show that the threat of exclusion, and later the experience of it, acts as a non-financial social disincentive to free ride. Lower contributors receive more exclusion tickets, and the presence of the exclusion mechanism reverses the typical decline in contributions. Moreover, experiencing exclusion strengthens the effectiveness of the subsequent exclusion threat. Willingness to incur personal costs to assign exclusion tickets increases over time. This pattern is mainly driven by normative expectations, particularly among individuals who perceive low tolerance for deviation as group contributions become more dispersed. In the absence of financial disincentives, these patterns show how non-financial incentives, shaped by more cooperative normative expectations, can foster group coordination and higher public-good contributions.

The Australian Carbon Credit Unit (ACCU) Scheme provides opportunities for farmers to benefit financially from sequestering additional carbon in their soils. The Scheme assesses additionality using a ‘newness’ test; if one of a list of eligible farming practices was not used by a farmer in a 5‐year baseline period, its use within the project is considered to be additional. However, this approach is unable to detect non‐additionality in cases where farmer adoption of the eligible farming practice is increasing in the absence of carbon credits. This analysis uses parameters from the actual scheme, combined with soil carbon sequestration rates informed by scientific research, and calculates net financial benefits to farmers from participation in the soil carbon method of the ACCU Scheme. In most scenarios modelled in this study, the net benefits to farmers from participating in the soil carbon scheme are small relative to other costs and revenues from farming (assuming that a recognised existing design problem with the scheme that is causing over‐crediting is corrected). As a result, the area of additional projects is relatively small and can easily be outweighed by non‐additional projects. Therefore, the expenditure on ACCUs required to achieve a tonne of genuine CO ₂ ‐e mitigation can be extremely high: up to 80 times higher than the cost of an ACCU in one of the scenarios explored. The prospects of developing a system that accurately assesses the additionality of soil carbon projects seem remote.

Various policy interventions can be implemented to motivate individuals to adopt pro-environmental landscaping behaviours. 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 then estimate adoption intention under different support programs using a choice experiment, also considering social norms. We find 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.

Since its establishment in 1957, the Australasian Agricultural and Resource Economics Society (AARES) has gone through many changes but has continued to be highly valued by its members. In this paper, we update and expand Keith Campbell's earlier history of the Society. Notable changes include, the slowly shifting emphasis of members' work from farm issues towards resources, environment and development; changes to the name of the Society and its Journal; increasing internationalisation; the professional roles and interests of AARES members; the gender balance of the Society; and the number and types of awards given. Major changes in government departments and universities have had various impacts on AARES. The history highlights the intellectual and practical contributions made by AARES members and also the camaraderie that is a key benefit of being part of the Society.JEL Classification: A14

Increasing the area of drought‐tolerant native vegetation in urban parks is a potential strategy to adapt to growing water scarcity under climate change. With a case study in Perth, Australia, we undertake benefit–cost analyses to understand the potential impacts of modifying urban park landscape designs away from conventions dominated by watered grass towards alternatives with more native vegetation. Considering the costs of establishing and maintaining alternative designs alone, we find that local governments can save money by reducing the extent of watered grass cover in parks. Incorporating nonmarket benefits into the analyses provides evidence of positive community net benefits from making changes to conventional park designs. We show that an alternative park design featuring a mix of 60% native vegetation and 40% watered grass delivers the highest net benefits for both new park development and retrofits to existing parks. These findings suggest it is time to rethink urban park design norms in Australia to better align landscaping choices with community preferences under a changing climate.

Food safety is an issue of growing concern in many developing countries. Threats to food safety in Vietnam include contamination with toxic chemicals, microbiological hazards and adulterated food. To determine Vietnamese consumers' willingness to pay for food safety of pork and vegetables, a discrete choice experiment was employed in the cities of Hanoi and Haiphong. Principal factor analysis and mixed logit models reveal that urban consumers are, on average, willing to pay considerable price premiums for food safety attributes. On average, consumers are willing to pay a price premium of 244% for vegetables produced with the safe application of pesticides, 70% premium for pork processed in certified abattoirs that assure pork safety and 67% price premium for pork if the convenience attribute is satisfied. Regarding vegetables, there is considerable heterogeneity in the extent to which consumers are willing to pay for growth‐hormone‐free vegetables, depending on their education, and in perceptions towards food safety risks resulting from chemical hazards and foodborne illness in Vietnam. For pork, if consumers believe that contaminated food could cause life‐threatening risks for people, they are willing to pay up to 102% more than the current market price for hormone‐free and drug‐free pork. The factor representing consumers' trust in food safety influences their WTP for traceability and clean water attributes. Moreover, consumer's self‐health evaluation influenced their WTP for pork traceability. Almost all consumers prefer the convenience of being able to purchase vegetables and pork nearby.

Policymakers must make management decisions despite incomplete knowledge and conflicting model projections. Little guidance exists for the rapid, representative, and unbiased collection of policy-relevant scientific input from independent modeling teams. Integrating approaches from decision analysis, expert judgment, and model aggregation, we convened multiple modeling teams to evaluate COVID-19 reopening strategies for a mid-sized United States county early in the pandemic. Projections from seventeen distinct models were inconsistent in magnitude but highly consistent in ranking interventions. The 6-mo-ahead aggregate projections were well in line with observed outbreaks in mid-sized US counties. The aggregate results showed that up to half the population could be infected with full workplace reopening, while workplace restrictions reduced median cumulative infections by 82%. Rankings of interventions were consistent across public health objectives, but there was a strong trade-off between public health outcomes and duration of workplace closures, and no win-win intermediate reopening strategies were identified. Between-model variation was high; the aggregate results thus provide valuable risk quantification for decision making. This approach can be applied to the evaluation of management interventions in any setting where models are used to inform decision making. This case study demonstrated the utility of our approach and was one of several multimodel efforts that laid the groundwork for the COVID-19 Scenario Modeling Hub, which has provided multiple rounds of real-time scenario projections for situational awareness and decision making to the Centers for Disease Control and Prevention since December 2020.