AJAE《美国农业经济学期刊》2026年第108卷第3期目录及摘要
官网链接：
https://onlinelibrary.wiley.com/toc/14678276/2026/108/3目录 (Table of Contents)
Spatial price competition and buyer power in the U.S. beef packing industryGianCarlo Moschini, T. Jake SmithFarmers' pro-social motivations and willingness-to-accept in markets with public goodsJill Fitzsimmons, Hikaru Hanawa Peterson, Nathalie LavoieWhat are the carbon services from cover-crop adoption worth from farmers' perspective?Saurav Raj Kunwar, Robert G. Chambers, Laura F. Gentry, Teresa SerraSize-based regulation and water quality: Evidence from the Iowa hog industryChen-Ti Chen, Gabriel E. Lade, John M. Crespi, David A. KeiserEvaluating large-scale government investments in fertilizer adoption: The Ethiopian experienceThomas Assefa, Ellen McCullough, Guush BerhaneRainfall timing, forage growth, and insuring forage: Linking producer perceptions to observational data降雨时机、饲草生长与饲草保险：将生产者认知与观测数据联系起来Brittney Goodrich, Jisang Yu, Kelly Davidson, Gyuhyeong GohSinking peatlands: Optimal control of subsidenceSuphi Sen, Dewy Verhoeven, Hans-Peter WeikardOptimal timing and rate of nitrogen fertilizer use: An integrated network technology approachTihomir Ancev, Moriah BostianA flexible model of food security: Estimation and implications for predictionWill Davis, Jose Xilau, Rusty Tchernis, Christian Gregory摘要 (Abstracts)
Spatial price competition and buyer power in the U.S. beef packing industryGianCarlo Moschini, T. Jake SmithAbstract: We develop a spatially-explicit model of the U.S. beef packing industry to study key questions related to competition in an oligopsony setting. Cattle supplies are modeled at the county level, and packing plants' location, capacity, and ownership are taken as given. Packers procure negotiated cattle by competing in prices in each local (county) market, while accounting for transportation costs and pre-existing contracted supplies (alternative marketing arrangements). The model, calibrated to match observed 2022 data, is solved for the Bertrand-Nash equilibrium prices. The computed markdown in the price packers pay for fed cattle is decomposed into three components: the portion due to the inherent spatial oligopsony power; the amount due to an aspect of market concentration (firms owning multiple plants); and the component due to contracting. We find that markdowns are moderate, about $3.69/cwt or 2.6% of the fed cattle price, on average. About 54% of this markdown is due to the spatial configuration of plants, 40% is due to pre-contracted supplies, and only 6% of the markdown is attributed to multi-plant ownership by firms. Separately from markdowns, capacity constraints are found to lower fed cattle prices by 0.8% on average. Beyond the baseline, simulated counterfactual scenarios highlight specific policy-relevant questions. Markdowns are reasonably robust across counterfactuals, decreasing only modestly when plants operate independently or the use of contracting is limited. Across all counterfactual scenarios, cattle prices per se are most affected by tightening capacity constraints (as arising from a major plant closure or an upward swing in the cattle cycle).我们构建了一个空间显式的美国牛肉加工行业模型，以研究寡头垄断市场中的竞争问题。牛供应在县级层面建模，加工厂的位置、产能和所有权被视为给定条件。加工商通过在各地方（县）市场进行价格竞争来采购议价牛，同时考虑运输成本和已有的合约供应（替代营销安排）。该模型经过校准以匹配2022年观测数据，并求解伯兰特-纳什均衡价格。我们将加工商为育肥牛支付的价格中的加价幅度分解为三个部分：固有的空间寡头垄断力量、市场集中度（企业拥有多个加工厂）以及合约因素。研究发现加价幅度适中，平均约为每英担3.69美元或育肥牛价格的2.6%。其中约54%的加价源于加工厂的空间布局，40%源于预签合约供应，仅6%的加价归因于企业的多厂所有权。除加价外，产能约束平均使育肥牛价格降低0.8%。在基准情景之外，模拟的反事实情景突显了特定的政策相关问题。加价在各种反事实情景中具有相当强的稳健性，只有在工厂独立运营或合约使用受限时才会适度下降。在所有反事实情景中，牛价格本身受产能约束趋紧的影响最大（如主要工厂关闭或牛周期上行）。全文链接：
https://doi.org/10.1111/ajae.70003Farmers' pro-social motivations and willingness-to-accept in markets with public goodsJill Fitzsimmons, Hikaru Hanawa Peterson, Nathalie LavoieAbstract: To explain how some farmers' decisions may diverge from profit-maximization, we incorporate proactive social preferences for public goods in an expected utility framework, in addition to reactive risk preferences to uncertainty. We offer empirical evidence that proactive preferences influence farmers' decisions alongside reactive preferences by combining a discrete choice experiment, a dictator game, and the Eckel-Grossman risk elicitation method. In our application, farmers choose between selling to origin-identified (OI) markets, which may provide public goods but involve uncertainty, and to wholesale markets, which offer certainty but do not provide public goods. Farmers are heterogeneous in their valuation of OI markets, but, on average, are willing to accept loss in profit to sell to OI markets. This willingness-to-accept is partially explained by farmers' social preferences, even when controlling for risk preferences. Our results show that when evaluating policies, failure to consider either social or risk preferences leads to considerably different outcomes. To increase sales through OI markets and support the perceived associated public goods, policymakers could leverage farmers' preferences for these markets with carefully designed incentives.为解释为何部分农民的决策可能偏离利润最大化目标，我们在期望效用框架中引入了对公共品的主动社会偏好，以及面对不确定性的被动风险偏好。通过结合离散选择实验、独裁者博弈和Eckel-Grossman风险诱导方法，我们提供了主动偏好与被动偏好共同影响农民决策的经验证据。在我们的应用中，农民在两种市场之间进行选择：产地标识市场（可能提供公共品但存在不确定性）和批发市场（确定性强但不提供公共品）。农民对产地标识市场的估值存在异质性，但平均而言愿意接受利润损失以向产地标识市场销售。即使在控制风险偏好的情况下，这种意愿接受价格也部分可由农民的社会偏好解释。我们的研究结果表明，在评估政策时，如果未能考虑社会偏好或风险偏好，将导致截然不同的结果。为通过产地标识市场增加销售额并支持相关的公共品，政策制定者可以通过精心设计的激励措施来利用农民对这些市场的偏好。全文链接：
https://doi.org/10.1111/ajae.70004What are the carbon services from cover-crop adoption worth from farmers' perspective?Saurav Raj Kunwar, Robert G. Chambers, Laura F. Gentry, Teresa SerraAbstract: We derive shadow prices of carbon services provided by cover crops relative to non-cover-crop agricultural practices, accounting for carbon sequestration and greenhouse gas (GHG) emissions. We model the agricultural technology by integrating crop production, carbon sequestration, and GHG emissions. We derive a novel function representation of our technology using a data envelopment analysis (DEA). We then calculate shadow prices based on the dual representation of the technology and compare shadow prices between cover-crop and non-cover-crop fields. We find that the carbon sequestration and the GHG emissions reduction services from cover-crop fields relative to non-cover-crop fields are worth USD 17.88 and USD 9.42 per acre, respectively. We compare shadow prices to payments from an incentive program aimed at promoting cover-crop adoption, thereby highlighting the economic feasibility and potential barriers to adopting sustainable practices.我们推导了覆盖作物相对于非覆盖作物农业实践所提供的碳服务的影子价格，综合考虑了碳固存和温室气体排放。我们通过整合作物生产、碳固存和温室气体排放来建模农业技术。利用数据包络分析方法，我们推导出技术的新型函数表示形式。然后基于技术的对偶表示计算影子价格，并比较覆盖作物田块与非覆盖作物田块的影子价格。研究发现，覆盖作物田块相对于非覆盖作物田块的碳固存服务和温室气体减排服务价值分别为每英亩17.88美元和9.42美元。我们将影子价格与旨在促进覆盖作物采纳的激励计划支付进行比较，从而凸显了采纳可持续实践的经济可行性和潜在障碍。全文链接：
https://doi.org/10.1111/ajae.70005Size-based regulation and water quality: Evidence from the Iowa hog industryChen-Ti Chen, Gabriel E. Lade, John M. Crespi, David A. KeiserAbstract: The growing prevalence of animal feeding operations (AFOs) in the United States raises concerns among the public and regulators about their impact on local environmental quality. By linking historical regulatory records of AFOs in Iowa to downstream surface water pollution monitors, this paper studies the effects of the 2003 Clean Water Act regulations that targeted water pollution from the largest hog AFOs. The regulation decreased ammonia concentrations downstream of large hog AFOs by 6-8 percentage points. We find limited to no evidence of improvement for dissolved oxygen and phosphorus concentrations. Pollution reductions are largest during heavy precipitation months, consistent with the regulations reducing on-site spills and nutrient runoff from local fields. However, we find that pollution increased downstream from mid-sized hog AFOs, which were exempt from the updated regulations. Given the growth in the number of mid-sized facilities relative to large AFOs, we estimate that the regulation had little discernible impact on overall water quality.美国动物饲养操作的日益普遍引发了公众和监管机构对其对当地环境质量影响的担忧。通过将爱荷华州动物饲养操作的历史监管记录与下游地表水污染监测数据相关联，本文研究了2003年《清洁水法案》中针对大型生猪饲养操作水污染监管规定的影响。该监管使大型生猪饲养操作下游的氨浓度降低了6-8个百分点。我们发现在溶解氧和磷浓度方面的改善证据有限或不存在。污染减少在强降水月份最为显著，这与监管减少了现场泄漏和当地农田养分径流相一致。然而，我们发现中型生猪饲养操作（免于新规定约束）下游的污染有所增加。考虑到中型设施相对于大型饲养操作数量的增长，我们估计该监管对整体水质量的影响微乎其微。全文链接：
https://doi.org/10.1111/ajae.70006Evaluating large-scale government investments in fertilizer adoption: The Ethiopian experienceThomas Assefa, Ellen McCullough, Guush BerhaneAbstract: We evaluate the impact of a large Government of Ethiopia intervention to raise fertilizer supply by establishing five fertilizer blending facilities supplying fertilizers tailored to local soil nutrient profiles. We rely on the phased geographic rollout of blending facility establishment to identify the causal effect on fertilizer use, application rates, crop yields, gross crop revenue, and household consumption. Combining effects of multiple treatment periods, each estimated using a doubly robust difference-in-difference model, we find that the blending facilities increased the probability that farmers adopt the new blended fertilizers by 22 percentage points and increased application rates by 17 kg/ha (baseline adoption was zero). The facilities mostly induced farmers who previously used DAP to switch to NPS, and we find large decreases in DAP adoption (by 22 percentage points, 47% of the control group base mean) and application rates (16 kg/ha, 52% of the control group base mean) yet no impact on overall fertilizer adoption or application rates. Though the new blended fertilizers were expected to perform better, there is no evidence they improved crop yields, crop gross revenue, or household consumption. The effect of the intervention was more pronounced (with larger increases in NPS use and larger decreases in DAP use) for farms located near demonstration plots, which the Government used to train farmers about the agronomic response to the new fertilizers. We confirm results using three large-scale longitudinal datasets and show that they are robust to choices of specification, treatment definition, and inference assumptions.我们评估了埃塞俄比亚政府一项大规模干预措施的影响，该措施通过建立五家化肥混配厂来增加化肥供应，提供针对当地土壤养分状况定制的化肥。我们利用混配厂建设的地理分阶段推广来识别其对化肥使用、施用量、作物产量、作物总收入和家庭消费的因果效应。结合多个处理时期的效果，每个时期使用双重稳健双重差分模型进行估计，我们发现混配厂使农民采纳新型混配肥的概率提高了22个百分点，施用量增加了17公斤/公顷（基线采纳率为零）。这些设施主要促使此前使用磷酸二铵的农民转向氮磷硫肥，我们发现磷酸二铵的采纳率大幅下降22个百分点（对照基准均值的47%），施用量减少16公斤/公顷（对照基准均值的52%），但对总体化肥采纳率或施用量没有影响。尽管新型混配肥预期表现更好，但没有证据表明它们提高了作物产量、作物总收入或家庭消费。对于位于示范田附近的农场，干预效果更为显著（氮磷硫肥使用量增幅更大，磷酸二铵使用量降幅也更大），政府利用这些示范田对农民进行新型肥料农艺效果的培训。我们使用三个大规模纵向数据集验证了结果，并表明这些结果对规格选择、处理定义和推断假设具有稳健性。全文链接：
https://doi.org/10.1111/ajae.70007Rainfall timing, forage growth, and insuring forage: Linking producer perceptions to observational data降雨时机、饲草生长与饲草保险：将生产者认知与观测数据联系起来Brittney Goodrich, Jisang Yu, Kelly Davidson, Gyuhyeong GohAbstract: The timing and amount of rainfall are crucial in forage growth. Producer perceptions of the rainfall distribution are likely to influence their choices related to the Pasture, Rangeland, and Forage Rainfall Index insurance program. Because of the scarcity of forage production data, diversity of forage production systems, and climates throughout the United States, the correlation between the timing of rainfall and forage growth varies substantially. Using survey data from the northeastern and southeastern United States, we provide a snapshot of producers' perceptions on the relevant rainfall timing for forage growth. We also show that the perceptions do not align with actual insurance enrollment in the surveyed counties. We provide an empirical framework linking survey responses to county-level observational data using a Bayesian approach to determine the months when rainfall is most important for forage growth. We find that the producers' perceptions act as useful priors and are consistent with the county-level analysis. Our methods demonstrate a framework for combining survey data with secondary data to overcome data constraints that can be applied to other contexts beyond the Pasture, Rangeland, and Forage Rainfall Index insurance program.降雨的时机和数量对饲草生长至关重要。生产者对降雨分布特征的认知可能影响其与牧场、草地和饲草降雨指数保险计划相关的选择。由于饲草生产数据的稀缺性、饲草生产系统的多样性以及美国各地气候的差异，降雨时机与饲草生长之间的相关性存在显著差异。利用来自美国东北部和东南部的调查数据，我们提供了生产者对饲草生长相关降雨时机的认知快照。我们还发现这些认知与调查县的保险实际投保情况并不一致。我们构建了一个经验框架，使用贝叶斯方法将调查响应与县级观测数据联系起来，以确定降雨对饲草生长最为重要的月份。我们发现生产者的认知作为有用的先验信息，与县级分析结果一致。我们的方法展示了将调查数据与辅助数据相结合以克服数据约束的框架，该框架可应用于牧场、草地和饲草降雨指数保险计划之外的其他情境。全文链接：
https://doi.org/10.1111/ajae.70009Sinking peatlands: Optimal control of subsidenceSuphi Sen, Dewy Verhoeven, Hans-Peter WeikardAbstract: Land subsidence threatens the living conditions of about 1.2 billion people worldwide in deltaic regions characterized by soft top soil. Economic activity in these areas requires lowering groundwater levels to keep the land sufficiently dry, which leaves future generations worse off by accelerating subsidence and increasing future costs. This paper provides a model that recognizes this trade-off and yields analytical expressions for the groundwater level paths that optimally manage the dynamics of subsidence in agricultural lands. Applying our model to the paradigm case of Dutch peatlands, we find that accounting for dynamic efficiency increases welfare by more than 2.5% compared to a myopic benchmark, and these gains can be about 10% within reasonable parameter ranges. Our results support current proposals to reduce subsidence, even without considering additional social benefits from avoided carbon dioxide emissions.地面沉降威胁着全球约12亿居住在软土表层三角洲地区人口的生活条件。这些地区的经济活动需要降低地下水位以保持土地充分干燥，但这会加速沉降并增加未来成本，使后代处境恶化。本文提出了一个识别这一权衡关系的模型，并给出了在地下水位路径上的解析表达式，以最优方式管理农业用地的沉降动态。将模型应用于荷兰泥炭地的典型案例，我们发现考虑动态效率可使福利相比短视基准提高2.5%以上，在合理的参数范围内这些收益可达约10%。我们的研究结果支持当前减少沉降的提案，即使不考虑避免二氧化碳排放的额外社会效益也是如此。全文链接：
https://doi.org/10.1111/ajae.70010Optimal timing and rate of nitrogen fertilizer use: An integrated network technology approachTihomir Ancev, Moriah BostianAbstract: Both the rate and timing of crop fertilizer application play an important role in agricultural productivity. However, inefficient fertilizer use can significantly increase production costs, water pollution, and greenhouse gas emissions. To capture both the spatial heterogeneity and dynamic nature of this problem, we develop a multi-stage network production model, which links the sequential stages of crop growth within the overall crop production process. We use this framework to estimate nitrogen fertilizer application inefficiency and to determine the optimal rate and timing of fertilizer application. We apply this framework to wheat production at the field scale, using an agronomic simulation model calibrated to experimental data from Australia. Our results indicate that it is optimal to reduce the overall fertilizer application rate and to move away from the current practice of front-loading fertilizer in the initial stages of crop growth toward the intermediate stages. This can be achieved without compromising yields while also reducing nutrient losses.作物施肥的用量和时机对农业生产率都起着重要作用。然而，低效的化肥使用会显著增加生产成本、水污染和温室气体排放。为捕捉这一问题的空间异质性和动态特性，我们开发了一个多阶段网络生产模型，将作物生长的连续阶段与整体作物生产过程联系起来。利用这一框架，我们估计了氮肥施用的低效率，并确定了肥料施用的最优用量和时机。我们将该框架应用于田间尺度的小麦生产，使用基于澳大利亚实验数据校准的农学模拟模型。我们的研究结果表明，最优策略是降低总体施肥量，并将当前在作物生长初期集中施肥的做法转向生长中期施肥。这可以在不损害产量的同时减少养分损失。全文链接：
https://doi.org/10.1111/ajae.70011A flexible model of food security: Estimation and implications for predictionWill Davis, Jose Xilau, Rusty Tchernis, Christian GregoryAbstract: We propose a novel Bayesian Graded Response Model (BGRM) for measuring household-level food security and other latent traits. The BGRM produces continuous food security estimates along with household-level measures of estimation uncertainty. Unlike the USDA's official model, the BGRM accommodates both binary and ordered polytomous items. We further extend the model to allow for any combination of binary, ordered polytomous, and even continuous variables. To demonstrate the model's features, we estimate the BGRM using responses to the 10 adult core Food Security Module questions from the 2017-2018 National Health and Nutrition Examination Survey (NHANES). Results show non-trivial uncertainty in household-level food security estimates and overlap across USDA-defined food security categories. As a robustness check, we estimate the model with Current Population Survey data, finding qualitatively similar results. We illustrate an application of the continuous food security estimates by calculating Foster, Greer, and Thorbecke indices which capture the prevalence, depth, and severity of food insecurity. To demonstrate flexibility in variable selection, we also include a continuous variable, household-level monthly food spending, capturing both economic access and experiential food security information in a single latent construct. The adaptability of the BGRM positions it as a versatile tool for measuring food security and related latent traits, particularly when measures of uncertainty or a mix of different variable types are required. While the empirical application illustrates model capabilities, the primary contribution of the study is methodological.我们提出了一种新颖的贝叶斯分级响应模型，用于测量家庭层面的粮食安全及其他潜在特质。该模型能够提供连续的粮食安全估计值以及家庭层面的估计不确定性度量。与美国农业部的官方模型不同，该模型同时适用于二元和有序多分类项目。我们进一步扩展了该模型，允许包含二元、有序多分类甚至连续变量的任意组合。为展示模型特性，我们利用2017-2018年国家健康与营养调查中10个成人核心粮食安全模块问题的回答来估计该模型。结果显示家庭层面粮食安全估计中存在不可忽视的不确定性，且美国农业部定义的粮食安全类别之间存在重叠。作为稳健性检验，我们使用当前人口调查数据估计该模型，发现了性质相似的结果。我们通过计算Foster-Greer-Thorbecke指数（捕捉粮食不安全的普遍性、深度和严重程度）来说明连续粮食安全估计的应用。为展示变量选择的灵活性，我们还纳入了一个连续变量——家庭月度食品支出——在单一潜在构造中同时捕捉经济可及性和体验性粮食安全信息。该模型的适应性使其成为测量粮食安全及相关潜在特质的多功能工具，特别是在需要不确定性度量或混合不同类型变量时。虽然经验应用展示了模型能力，但本研究的主要贡献在于方法论。全文链接：
https://doi.org/10.1111/ajae.70012
