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Increasing production diversity and diet quality: Evidence from Bangladesh 提高生产多样性和饮食质量:来自孟加拉国的证据
IF 4.2 2区 经济学 Q1 Agricultural and Biological Sciences Pub Date : 2023-08-25 DOI: 10.1111/ajae.12427
Akhter Ahmed, Fiona Coleman, Julie Ghostlaw, John Hoddinott, Purnima Menon, Aklima Parvin, Audrey Pereira, Agnes Quisumbing, Shalini Roy, Masuma Younus

In the context of rural Bangladesh, we assess whether agriculture training alone, nutrition behavior communication change (BCC) alone, combined agriculture training and nutrition BCC, or agriculture training and nutrition BCC combined with gender sensitization improve: (a) production diversity, either on household fields or through crop, livestock, or aquaculture activities carried out near the family homestead; and (b) diet diversity and the quality of household diets. All treatment arms were implemented by government employees. Implementation quality was high. No treatment increased production diversification of crops grown on fields. Treatment arms with agricultural training did increase the number of different crops grown in homestead gardens and the likelihood of any egg, dairy, or fish production but the magnitudes of these effect sizes were small. All agricultural treatment arms had, in percentage terms, large effects on measures of levels of homestead production. However, because baseline levels of production were low, the magnitude of these changes in absolute terms was modest. Nearly all treatment arms improved measures of food consumption and diet with the largest effects found when nutrition and agriculture training were combined. Relative to treatments combining agriculture and nutrition training, we find no significant impact of adding the gender sensitization on our measures of production diversity or diet quality. Interventions that combine agricultural training and nutrition BCC can improve both production diversity and diet quality, but they are not a panacea. They can, however, contribute toward better diets of rural households.

在孟加拉国农村的背景下,我们评估了单独的农业培训、单独的营养行为沟通改变(BCC)、农业培训和营养BCC的结合,或农业培训和营养学BCC与性别敏感度的结合是否改善了:(a)家庭田地或作物、牲畜的生产多样性,或在家庭宅地附近进行的水产养殖活动;以及(b)饮食多样性和家庭饮食质量。所有治疗手段均由政府雇员实施。执行质量很高。没有任何处理增加了田间作物的生产多样化。经过农业培训的治疗组确实增加了在家庭花园中种植的不同作物的数量,以及任何鸡蛋、奶制品或鱼类生产的可能性,但这些影响的大小很小。就百分比而言,所有农业处理部门都对衡量宅基地生产水平产生了巨大影响。然而,由于基准生产水平较低,这些变化的绝对值幅度不大。几乎所有的治疗组都改进了食物消耗和饮食的测量,当营养和农业训练相结合时,效果最大。相对于农业和营养培训相结合的治疗,我们发现增加性别敏感度对我们的生产多样性或饮食质量的衡量没有显著影响。将农业培训和营养BCC相结合的干预措施可以提高生产多样性和饮食质量,但它们不是万能药。然而,他们可以为改善农村家庭的饮食做出贡献。
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引用次数: 0
State-contingent production technology formulation: Identifying states of nature using reduced-form econometric models of crop yield 状态-偶然生产技术公式:使用作物产量的简化形式计量经济模型确定自然状态
IF 4.2 2区 经济学 Q1 Agricultural and Biological Sciences Pub Date : 2023-08-16 DOI: 10.1111/ajae.12424
Raushan Bokusheva, Lajos Baráth

Conducting experiments can be time consuming and expensive, and may not always be reasonable. Therefore, empirical research often derives structural parameters based on observational data and reduced-form econometric models. The state-contingent approach presents a consistent conceptual framework for analyzing producer decisions under uncertainty. However, application of this structural modeling approach has been hampered by data constraints, particularly the lack of information for mapping producers' stochastic outputs onto a set of the states of nature representing different uncertain events. Consistent mapping of uncertainty is particularly critical in the context of multiple output production where weather shocks often have different effects across crops and in microeconometric analyses when unobserved farm heterogeneity may confound the effect of uncertainty. Our study demonstrates how the application of reduced-form approaches can overcome constraints of structural econometric modeling associated with the lack of relevant data and presents an approach for identifying states of nature in the context of multiple output production using reduced-form econometric models of crop yield. In an empirical application based on Hungarian farm accountancy data, we demonstrate that the proposed approach allows a consistent mapping of production uncertainty in crop farming, utilizes panel data structure, and controls for potential endogeneity due to unobserved farm heterogeneity. We anticipate the presented approach to be useful for developing further the state-contingent approach and to stimulate further studies combining the strengths of structural approaches and reduced-form models.

进行实验可能耗时且昂贵,而且可能并不总是合理的。因此,实证研究通常基于观测数据和简化形式的计量经济模型来推导结构参数。状态相关方法为分析不确定性下的生产者决策提供了一个一致的概念框架。然而,这种结构建模方法的应用受到数据约束的阻碍,特别是缺乏将生产者的随机产出映射到代表不同不确定事件的一组自然状态的信息。在多产量生产的背景下,天气冲击通常对作物产生不同的影响,而在微观计量分析中,未观察到的农场异质性可能混淆不确定性的影响,对不确定性的一致映射尤为重要。我们的研究证明了简化形式方法的应用如何克服与缺乏相关数据相关的结构计量经济建模的限制,并提出了一种使用作物产量的简化形式计量经济模型来识别多种产出生产背景下的自然状态的方法。在一个基于匈牙利农场会计数据的实证应用中,我们证明了所提出的方法允许对作物种植中的生产不确定性进行一致的映射,利用面板数据结构,并控制由于未观察到的农场异质性而产生的潜在内生性。我们预计所提出的方法将有助于进一步发展状态相关方法,并促进结合结构方法和简化模型的优势进行进一步研究。
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引用次数: 0
Quantifying co-benefits of water quality policies: An integrated assessment model of land and nitrogen management 量化水质政策的共同效益:土地和氮管理的综合评估模型
IF 4.2 2区 经济学 Q1 Agricultural and Biological Sciences Pub Date : 2023-08-08 DOI: 10.1111/ajae.12423
Weizhe Weng, Kelly M. Cobourn, Armen R. Kemanian, Kevin J. Boyle, Yuning Shi, Jemma Stachelek, Charles White

Due to the nature of nitrogen cycling, policies designed to address water quality concerns have the potential to provide benefits beyond the targeted water quality improvements. For example, actions to protect water quality by reducing nitrate leaching from agriculture also reduce emissions of nitrous oxide, a potent greenhouse gas. These positive effects, which are incidental to the regulation's intended target, are termed “co-benefits.” To quantify the co-benefits associated with reduced nitrate leaching, we integrate an economic model of farmer decision making with a model of terrestrial nitrogen cycling for the watershed surrounding Lake Mendota, Wisconsin, USA. Our modeling approach provides a framework that links air and water pollutants in an agri-environmental system and offers a direction for future studies. Our model results highlight the finding that the co-benefits from nitrous oxide abatement are substantial, and their inclusion increases the benefit–cost ratio of water quality policies. Consideration of these co-benefits has the potential to reverse the conclusions of benefit–cost analysis in the assessment of current water quality policies.

由于氮循环的性质,旨在解决水质问题的政策有可能带来目标水质改善之外的好处。例如,通过减少农业硝酸盐浸出来保护水质的行动也减少了一氧化二氮的排放,这是一种强大的温室气体。这些积极影响是该法规预期目标附带的,被称为“共同效益”。为了量化与减少硝酸盐浸出相关的共同效益,我们将农民决策的经济模型与美国威斯康星州门多塔湖周围流域的陆地氮循环模型相结合。我们的建模方法提供了一个将农业环境系统中的空气和水污染物联系起来的框架,并为未来的研究提供了方向。我们的模型结果强调了这一发现,即减少一氧化二氮带来的共同利益是巨大的,并且将其纳入其中会提高水质政策的效益-成本比。在评估当前水质政策时,考虑这些共同效益有可能推翻效益-成本分析的结论。
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引用次数: 0
Estimating habit-forming and variety-seeking behavior: Valuation of recreational birdwatching 习惯形成和多样性寻求行为的评估:休闲观鸟的价值
IF 4.2 2区 经济学 Q1 Agricultural and Biological Sciences Pub Date : 2023-08-08 DOI: 10.1111/ajae.12422
Todd Guilfoos, Priya Thomas, Sonja Kolstoe

Past experiences influence choices, and people's preferences for more similar (habit-forming) or different (variety-seeking) experiences are reflected in these choices. We develop a structural estimation framework to capture whether people are habit forming or variety seeking and apply it to the choice of recreation site. This research contributes to the revealed preference literature by demonstrating how to account for habit or variety-seeking behavior in recreation site choice models in a two-stage framework. Using this framework, we estimate similarity weights that reflect the birders habit formation and variety seeking preferences. Predicted probabilities from the first stage model are then incorporated into the second stage, a mixed logit recreation site choice model of bird watching trips from eBird, by their members. We find that including the dynamic elements of choice, specifically variety-seeking behavior, can double the estimated willingness to pay (WTP) for individual sites relative to the static model. Although our sample of bird watching trips taken by eBird members is a sample of convenience, these results suggest that static models of recreation site choice are a lower bound on our recreation demand WTP estimates. We find variety-seeking preferences are related to land cover and the site's fixed attributes, whereas habit formation appears for seasonality in the bird watching context.

过去的经历会影响选择,人们对更相似(习惯形成)或不同(寻求多样性)经历的偏好反映在这些选择中。我们开发了一个结构估计框架来捕捉人们是习惯形成还是追求多样性,并将其应用于娱乐场所的选择。本研究通过展示如何在两阶段框架中解释娱乐场所选择模型中的习惯或多样性寻求行为,为揭示偏好文献做出了贡献。利用这一框架,我们估计了反映鸟类习惯形成和多样性偏好的相似性权重。然后将第一阶段模型的预测概率纳入第二阶段,即eBird成员的观鸟旅行混合logit游憩地点选择模型。我们发现,与静态模型相比,包含动态选择元素,特别是多样性寻求行为,可以使单个站点的估计支付意愿(WTP)增加一倍。虽然我们对eBird会员观鸟旅行的样本是一个方便的样本,但这些结果表明,游憩地点选择的静态模型是我们的游憩需求WTP估计的下限。我们发现,寻求多样性的偏好与土地覆盖和地点的固定属性有关,而习惯的形成则与观鸟环境的季节性有关。
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引用次数: 0
Land use impacts of the Conservation Reserve Program: An analysis of rejected offers 保护储备计划对土地利用的影响:对被拒绝出价的分析
IF 4.2 2区 经济学 Q1 Agricultural and Biological Sciences Pub Date : 2023-08-06 DOI: 10.1111/ajae.12425
Andrew B. Rosenberg, Bryan Pratt

The Conservation Reserve Program is the largest agricultural land retirement program in the United States, with more enrolled acreage entering the program through a competitive auction called the General Signup than any other component. In this study, we assess the land use impacts of the Conservation Reserve Program by observing the land use decisions of parcels following the 2016 General Signup. We estimate land use impacts using a regression discontinuity design based on the Environmental Benefits Index, the program's selection and ranking mechanism. Our estimates largely rely on the auction design of the General Signup, such that we observe the land use decisions of rejected offers. We also use information on the rental rates of these offers to understand what the program pays to retire land in different uses. We estimate that a marginal acre of land enrolled in the Conservation Reserve Program replaces 0.30 acres in cropland, 0.25 acres in mixed forage, 0.32 acres in grassland, 0.12 acres in idle or fallow land, and 0.01 acres in timberland. We also find that enrollments from newly offered fields are more likely to displace cropland and less likely to displace grassland than returning fields. Consequently, we estimate that new enrollments lead to 47% greater reductions in water-driven erosion and 12% greater reductions in wind-driven erosion, compared to fields with prior enrollment.

保护储备计划是美国最大的农业用地退耕计划,通过名为 "普遍签约 "的竞争性拍卖进入该计划的注册耕地面积比其他任何计划都要多。在本研究中,我们通过观察 2016 年普遍签约后地块的土地使用决策来评估保护储备计划对土地使用的影响。我们使用基于环境效益指数(该计划的选择和排名机制)的回归不连续设计来估算土地使用的影响。我们的估算在很大程度上依赖于普遍签约的拍卖设计,因此我们可以观察到被拒绝出价的土地使用决策。我们还利用这些出价的租金信息来了解该计划为退还不同用途的土地所支付的费用。我们估计,加入保护储备计划的边际英亩土地可替代 0.30 英亩耕地、0.25 英亩混合饲料地、0.32 英亩草地、0.12 英亩闲置或休耕土地以及 0.01 英亩林地。我们还发现,与返回的田地相比,新提供的田地更有可能取代耕地,而取代草地的可能性较小。因此,据我们估计,与之前加入的田地相比,新加入的田地可使水力侵蚀减少 47%,风力侵蚀减少 12%。
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引用次数: 0
Farm-level responses to weather trends: A structural model 农场水平对天气趋势的响应:一个结构模型
IF 4.2 2区 经济学 Q1 Agricultural and Biological Sciences Pub Date : 2023-07-19 DOI: 10.1111/ajae.12421
Stefan Wimmer, Christian Stetter, Jonas Schmitt, Robert Finger

Assessing the effects of weather and climate on agricultural production is crucial for designing policies related to climate change adaptation and mitigation. A large body of literature has identified the detrimental effects of climate change on crop yields worldwide, and farm-level adaptation has been shown to mitigate the adverse effects on agricultural production. In this study, we employ a structural model to examine farm production responses to ongoing weather trends. We investigate how farmers adjust output and input decisions by estimating a system of output supply and input demand functions, controlling for nonrandom crop selection. Using panel data with 14,796 observations reflecting 1638 German crop farms (1996–2019), we find that both the expected and realized weather determine farmers' production decisions. In the event of a drought, the supply of most considered crops and the demand for fertilizer decrease. The drought shock has also lasting effects on farmers' production decisions, with a reduced supply of protein crops and an increased level of root crops production in subsequent years. These findings highlight the need to account for farm-level production responses when assessing weather and climate impacts.

评估天气和气候对农业生产的影响对于制定适应和减缓气候变化的相关政策至关重要。大量文献指出了气候变化对全球作物产量的不利影响,而农场层面的适应已被证明可减轻对农业生产的不利影响。在本研究中,我们采用结构模型来研究农业生产对持续天气趋势的反应。在控制非随机作物选择的前提下,我们通过估算产出供给和投入需求函数系统,研究农民如何调整产出和投入决策。通过使用反映 1638 个德国作物农场(1996-2019 年)的 14796 个观测值的面板数据,我们发现预期天气和实际天气都决定着农民的生产决策。在干旱情况下,大多数被考虑的作物的供应和化肥需求都会减少。干旱冲击也会对农民的生产决策产生持久影响,在随后几年中,蛋白质作物的供应量会减少,而根茎作物的产量会增加。这些研究结果突出表明,在评估天气和气候影响时,需要考虑农场一级的生产反应。
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引用次数: 0
Revisiting the size–productivity relationship with imperfect measures of production and plot size 用不完善的生产和地块大小测量重温规模与生产力的关系
IF 4.2 2区 经济学 Q1 Agricultural and Biological Sciences Pub Date : 2023-07-12 DOI: 10.1111/ajae.12417
Hailemariam Ayalew, Jordan Chamberlin, Carol Newman, Kibrom A. Abay, Frederic Kosmowski, Tesfaye Sida

Monitoring smallholder agricultural productivity growth, one of the targets of the Sustainable Development Goals, rests on accurate measures of crop production and land area. Existing methods and protocols for measuring smallholder production and plot size are prone to various sources and forms of mismeasurement. Inaccuracies in production and land area measurement are likely to distort descriptive and predictive inferences. We examine the sensitivity of empirical assessments of the relationship between agricultural productivity and land area to alternative measurement protocols. We implement six production and six land area measurement protocols, and show that most of these protocols differ systematically in their accuracy. We find that an apparent inverse size–productivity relationship in our data is fully explained by measurement error in both production and plot size. Moreover, we show that some of the previously used “gold standard” measures are themselves prone to nonclassical measurement error, and hence can generate spurious inverse size–productivity findings. Our results also show that slight improvements in the precision of objective measures significantly reduce the inferential bias associated with the size–productivity relationship.

监测小农户农业生产力增长是可持续发展目标的目标之一,取决于对作物生产和土地面积的准确衡量。测量小农户生产和地块面积的现有方法和协议容易产生各种来源和形式的错误测量。生产和土地面积测量的不准确可能会扭曲描述性和预测性推断。我们研究了农业生产力和土地面积之间关系的实证评估对替代测量协议的敏感性。我们实施了六个生产和六个陆地面积测量协议,并表明这些协议中的大多数在准确性方面存在系统性差异。我们发现,我们的数据中明显的大小-生产力反比关系可以通过生产和地块大小的测量误差来充分解释。此外,我们还表明,一些以前使用的“金标准”度量本身就容易出现非经典的测量误差,因此可能会产生虚假的反大小-生产率结果。我们的结果还表明,客观测量精度的轻微提高显著降低了与规模-生产力关系相关的推断偏差。
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引用次数: 0
Structural identification of weather impacts on crop yields: Disentangling agronomic from adaptation effects 气候对作物产量影响的结构识别:从适应效应中分离农艺效应
IF 4.2 2区 经济学 Q1 Agricultural and Biological Sciences Pub Date : 2023-07-10 DOI: 10.1111/ajae.12420
François Bareille, Raja Chakir

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.

大量文献通过估算以天气和个人固定效应为条件的作物产量简化模型,评估了气候变化对农业生产的影响。得到的估计值通常被解释为农民适应后天气对产量的影响。然而,很少有尝试能证明农民确实适应了天气变化,也没有人证实这些调整确实对作物产量产生了影响。在此,我们的目标是通过建立一个结构模型,明确考虑植物对天气的生物物理反应和农民对天气的行为反应,从而揭示天气如何影响农业生产。考虑到在生长季节通过施用化肥和农药进行适应,我们的方法使我们能够区分 "直接 "天气影响(即天气变化对植物生长本身的农艺影响)和通过农民的投入选择产生的 "间接 "天气影响(即适应影响)。我们利用法国默兹省的农场级数据对基本结构模型进行了估计,这些数据提供了按作物划分的化肥和农药使用详情。我们的结果表明,在大量的敏感性分析中,简化形式估算和结构估算显示了类似的天气对作物产量的影响。我们的结构估算结果表明,适应效应相当可观,农民的调整降低了气候变化的预期损害。在我们的示例中,农民的调整抵消了未来气候变暖对作物产量造成的四分之一到三分之二的负面农艺影响。我们的分析表明,常用的作物产量简化形式模型本质上捕捉到了这些季节内对天气的行为反应。
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引用次数: 0
Information acquisition and the adoption of improved crop varieties 信息获取和改良作物品种的采用
IF 4.2 2区 经济学 Q1 Agricultural and Biological Sciences Pub Date : 2023-07-05 DOI: 10.1111/ajae.12419
Awudu Abdulai

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.

关于创新农业技术的益处的信息和知识不足仍然是发展中国家小农采用技术的主要制约因素。新技术采用率低是小农生产率低和贫困率高的原因之一,特别是在非洲。本文简要回顾了社会网络与技术扩散的相关文献,认为社会网络的扩散潜力尚未得到充分挖掘。然后,我介绍了两项关于社会网络对加纳和埃塞俄比亚改良作物品种采用影响的实证研究的结果。结果表明,农民的同伴收养决定和经验,以及来自受过培训的发展代理人的信息对他们的收养决定产生了积极的统计影响。我还发现,网络内部分割程度较低、信息可信度高、信息流量的有效性和高效性等网络结构特征,有利于提高作物改良品种的信息获取和传播速度。
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引用次数: 1
Do obese and nonobese consumers respond differently to price changes? Implications of preference heterogeneity for obesity-oriented food taxes and subsidies 肥胖消费者和非肥胖消费者对价格变化的反应不同吗?肥胖导向的食品税收和补贴偏好异质性的含义
IF 4.2 2区 经济学 Q1 Agricultural and Biological Sciences Pub Date : 2023-06-29 DOI: 10.1111/ajae.12418
Chen Zhen, Yu Chen, Biing-Hwan Lin, Shawn Karns, Lisa Mancino, Michele Ver Ploeg

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.

食品需求的偏好异质性对旨在提高饮食质量和减少肥胖的有针对性的和基础广泛的税收和补贴具有重要的健康和公平影响。我们利用具有全国代表性的 "全国家庭食品采购和购买调查 "的数据,研究了肥胖在家庭和外出购买食品中的作用。我们开发了一种方法,将复杂的调查设计和零售扫描仪数据纳入具有内生价格和截断购买量的 21 种商品精确仿射石指数需求系统的估计中。我们发现了与家庭成员肥胖状况相关的重大偏好异质性。反事实模拟发现:(1) 甜饮料税能有效提高低收入肥胖消费者购买食品的健康性;(2) 蔬菜水果补贴的营养益处主要集中在非肥胖消费者身上,肥胖消费者的健康饮食指数几乎没有提高,但其购买的总卡路里却有所增加;(3) 由不健康食品税全额资助的财政中性健康食品补贴在经济和营养方面对非肥胖消费者的益处大于对肥胖消费者的益处。这些研究结果表明,降低健康食品价格而不提高不健康食品的成本不太可能减少肥胖。支持同时对不健康食品征税和对健康食品进行补贴的政策制定者应注意这一政策对肥胖消费者和低收入人群的分配影响。
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引用次数: 0
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American Journal of Agricultural Economics
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