American Journal of Agricultural Economics最新文献

A large literature has assessed the impacts of climate change on agricultural production by estimating reduced-form models of crop yields conditionally on weather and individual fixed effects. The estimates obtained are usually interpreted as the weather impacts on yields once farmers have adapted. Yet, few attempts have documented that farmers do adapt to weather, and none have verified that these adjustments actually impact crop yields. Our objective here is to unpack how weather affects agricultural production by developing a structural model that explicitly accounts for both the plants' biophysical and farmers' behavioral responses to weather. Considering adaptation during the growing season through fertilizer and pesticide applications, our approach allows us to distinguish the “direct” weather effects (i.e., the agronomic impacts of weather changes on plant growth per se) from the “indirect” weather effects via farmers' input choices (i.e., the adaptation impacts). We estimate the underlying structural model using farm-level data from the Meuse French department, which provides details of fertilizer and pesticide uses by crop. We show that the reduced-form and structural estimates indicate similar weather impacts on crop yields, for a large range of sensitivity analyses. Our structural estimates indicate that the adaptation effects are sizable and that farmers' adjustments reduce projected damage from climate change. In our illustrative case, farmers' adaptation offsets between one-quarter to two-thirds of the negative agronomic impacts of future warming on crop yields. Our analyses exhibit that commonly used reduced-form models of crop yields inherently capture these within-season behavioral responses to weather.

Inadequate information on the benefits of and knowledge about innovative agricultural technologies continue to be a major constraint to technology adoption among smallholder farmers in developing countries. The low adoption of new technologies is one of the causes of low productivity and high poverty incidence among smallholder farmers, particularly in Africa. In this paper, I briefly review the literature on social networks and technology diffusion, and argue that the diffusion potential of social networks is underexplored. I then present results from two empirical studies on the impact of social networks on the adoption of improved crop varieties in Ghana and Ethiopia. The results reveal that farmers' peer adoption decisions and experiences, as well as information from trained development agents positively and statistically influence their adoption decisions. I also find that network structural characteristics such as lower segmentation within networks, high credibility of the information, and high effectiveness and efficiency of the amount of information flow tend to improve information acquisition and speed up diffusion of improved crop varieties.

Preference heterogeneity in food demand has important health and equity implications for targeted and broad-based taxes and subsidies intended to enhance diet quality and reduce obesity. We study the role of obesity in the purchases of food at home and food away from home using data from the nationally representative National Household Food Acquisition and Purchase Survey. We develop a method for incorporating the complex survey design and retail scanner data into the estimation of a 21-good Exact Affine Stone Index demand system with endogenous prices and truncated purchases. We find significant preference heterogeneity associated with the obesity status of household members. Counterfactual simulations find that (1) a sweetened beverage tax is effective in increasing the healthfulness of purchases by lower income obese consumers; (2) the nutritional benefits of a fruit and vegetable subsidy are concentrated on nonobese consumers with little improvement in obese consumers' Healthy Eating Index and an increase in their total calories purchased; and (3) a fiscally neutral healthy food subsidy fully funded by an unhealthy food tax benefits nonobese consumers both financially and nutritionally more than it does obese consumers. These findings show that lowering healthy food prices without raising the cost of unhealthy foods is unlikely to reduce obesity. Policymakers in favor of a systems approach of simultaneously taxing unhealthy foods and subsidizing healthy foods should be mindful of the distributional effects of this policy on obese consumers and the lower income population.

Conservation practices used on agricultural cropland can provide important ecosystem services. The United States relies largely on voluntary programs to incentivize adoption of conservation practices, but the success of these efforts relies on good program design. We use a choice experiment to evaluate farmers' willingness to adopt more intensive in-field conservation practices (continuous no-till, conservation crop rotation, cover crops, and variable rate application of inputs) using a nonlinear extended expected utility framework that incorporates risk under a conservation contract. We contribute to the literature by providing insights regarding producers' preference for incentive payment mechanism (federal program or carbon market) and the incentive payment needed to induce additionality and practice continuity. We find that although an additional payment might be needed to promote practice continuity among farmers who have previously adopted cover crops, in the case of continuous no-till, adopters might be willing to forgo additional payment to continue benefiting from the use of this practice. Our results also revealed producers prefer conservation contracts accruing higher off-farm environmental benefits and federally administered over carbon market programs. This is an important result given an increased public interest in climate change and new proposed carbon mitigation policies and private carbon market initiatives.

In the United States, agriculture is responsible for the majority of consumptive water use. To reduce consumptive use in water scarce regions, policymakers have implemented a number of costly interventions. These interventions range from land retirement to subsidies that encourage the adoption of efficient irrigation technologies. In nonagricultural contexts, costly policy interventions have been complemented by low-cost interventions inspired by behavioral economics. Whether these behavioral interventions are effective in the context of commercial farming is not well understood. In a preregistered, randomized field intervention, we estimate the impact of social (peer) comparisons on agricultural groundwater users in Colorado and Kansas. More than three thousand irrigators were randomized to receive either an annual peer comparison or no comparison. The peer comparison contrasted each irrigator's groundwater use to the distribution of use by neighboring irrigators. The comparison intervention reduced average annual groundwater use by 4.05% [95% CI (−5.87%, − 2.21%)], resulting in an aggregate reduction of more than 21,000 acre-feet per year at a cost less than $1.31 per acre-foot conserved. The estimated treatment effect was larger among irrigators with lower pre-intervention water use. In the 3-year experiment, we observed no evidence that the treatment effect substantially attenuated over time. We did, however, detect within-irrigator spillovers in the treatment group: groundwater use also declined among wells that were not included in the peer comparisons (peer comparisons included a maximum of three wells). The results imply that social comparisons can be a cost-effective tool, alongside other policy interventions, aimed at reducing agricultural water use.

We analyze how individual risk aversion changes in response to shocks in an agrarian setting, and the role of changes in yields and prices as two potential channels. To do so we specify a theoretical model that describes temporal alterations in risk aversion. Empirically, we test the model's proposition by combining individual-level panel data with historical rainfall data for rural Thailand and Vietnam. We find that rainfall shocks increase individuals risk aversion, whereby the largest effects are observed among households that are net buyers of food commodities. Regarding potential channels, only prices seem to explain–and even then just to a very small extent–the increase in net buyers' risk aversion. Our findings imply that shocks can increase risk aversion, and, in the absence of functioning credit and insurance markets, may ultimately lead to decisions that perpetuate poverty.

Taxation is frequently implemented to discourage the consumption of sugary beverages. Despite their popularity, little is known about the impacts of taxes when sellers practice price discrimination. To address this issue, we use a standard nonlinear pricing model with one product and two buyer types to study the effects of taxation on (i) consumption, (ii) consumer and producer surpluses, and (iii) the seller's choice of market segmentation scheme. We find that a tax would lead to reductions in consumption, consumer surplus, and expected profit. Additionally, the measure increases the likelihood that the sellers would exclude buyers with low preferences for the beverage to exclusively serve buyers with high willingness to pay for the product.

The Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) is the third largest food assistance program in the United States. Child participants lose WIC in the month following their fifth birthday. We use this exogenous program rule for identification and find diet quality declines nearly 20%, on average, for those who have yet to transition into kindergarten. Decreases are mainly driven by reduced consumption of healthier WIC-targeted foods. A quantile regression discontinuity approach reveals children prone to lower quality diets experience the largest decreases in diet quality, reaching nearly 30%, whereas those prone to higher quality diets experience no aging-out-of-WIC effects. There are no effects on calorie consumption, regardless of school attendance, indicating caregivers maintain diet quantity for children at the expense of diet quality. Policy implications include allowing children to stay on WIC until they enter kindergarten. We calculate back-of-the-envelope program costs over the next 5 years for such a “kindergarten-roll-off” WIC policy under current rules and newly proposed rules to realign WIC packages with the Dietary Guidelines for Americans. Under current rules, costs would average $112 million over the next 5 years (2024–2028), or about 2% of total program costs. Under proposed rule changes, kindergarten-roll-off costs would average $144 million per year, or 2.25% of total program costs.

Dollar stores have become the fastest-growing retail format in the United States. However, there is considerable controversy regarding their entry, particularly into markets without grocery stores, and concerns that dollar-store entry decisions are motivated by preemptive incentives. In this paper, we aim to study the market entry of dollar stores as an equilibrium phenomenon and to examine their impact on competing store formats in a dynamic environment. We use census-tract level data and develop a dynamic model of oligopolistic competition to estimate the impact of dollar store entry on the equilibrium entry decisions of other retailers of the same format and other formats. We find that supermarkets and other large-format owners thrive as dollar-store expansion removes their “competitive fringe” in shared markets, whereas other small-format stores (other dollar stores, convenience stores, and superettes) do not. Our findings have broad implications for the effect of dollar store entry on consumer welfare, as dollar-store entry is not associated with grocery-store exit but rather the exit of other small-format stores.

Shark incidents are rare and graphic events, and their consequences can influence the behavior of beach users, including bathers, to a great extent. These incidents can be thought of as a fearsome risk that may lead decision makers to overreact or respond with inaction. This paper examines the reaction of recreational beach users, including bathers, to changes in the risk of shark incidents. In addition to valuing recreational visits to Durban Beach, South Africa, we study the reaction of beach visitors to a hypothetical scenario in which protective shark nets, deployed in coastal waters to protect bathers, are to be removed. To examine potential heterogeneity of the treatment effect in a travel cost-contingent behavior model, we develop a semiparametric multivariate Poisson lognormal (MPLN) model to jointly analyze observed and stated visit counts. Results show that removing protective shark nets at Durban beach would decrease recreational visits by more than 20%. Applying the semiparametric MPLN model we further find that both the value of a recreational visit and the predicted change in visitation rates vary as a function of whether recreationists usually enter the water, whether they have heard of previous shark incidents, and their general risk attitude.