JAE 2023年第74卷第1期目录及摘要

全文链接：

https://onlinelibrary.wiley.com/toc/14779552/2023/74/1

PRESIDENTIAL ADDRESS

Agricultural policies and food systems: Priorities for indicator development

Jonathan Brooks

ORIGINAL ARTICLES

Ride the trend: Is there spread momentum profit in the US commodity markets?

Quanbiao Shang,  Teresa Serra,  Philip Garcia

Can medium-scale farms support smallholder commercialisation and improve welfare? Evidence from Nigeria

Lenis Saweda O. Liverpool-Tasie,  Ahmed Salim Nuhu,  Titus Awokuse,  Thomas Jayne,  Milu Muyanga,  Adebayo Aromolaran,  Adesoji Adelaja

Utilising farm-level panel data to estimate climate change impacts and adaptation potentials

Abdul Quddoos,  Klaus Salhofer,  Ulrich B. Morawetz

Are agro-clusters pro-poor? Evidence from Ethiopia

Martin Paul Jr Tabe-Ojong,  Guyo Godana Dureti

Understanding the variation in estimates of off-farm labour supply elasticities: A meta-analysis

Rakhe Balachandran,  Jerrod Penn,  Maria Bampasidou

Institutional quality and the duration of agri-food trade flows

Helena Engemann,  Yaghoob Jafari,  Thomas Heckelei

The (in)stability of farmer risk preferences

Robert Finger,  David Wüpper,  Chloe McCallum

Mobilising the public to fight poverty using anti-poverty labels in online food markets: Evidence from a real experimental auction

Yu Jiang,  H. Holly Wang,  Shaosheng Jin

Are farmers ‘efficient but poor’? The impact of crop choices on technical efficiency and poverty in Nigeria

Chisom Lotanna Ubabukoh,  Katsushi S. Imai

Predator or prey? Effects of farm growth on neighbouring farms

Franziska Appel,  Alfons Balmann

Input subsidies and crop diversity on family farms in Burkina Faso

Sibbir Ahmad,  Melinda Smale,  Veronique Theriault,  Eugenie Maiga

Early growing season weather variation, expectation formation and agricultural land allocation decisions in Ethiopia

Musa Hasen Ahmed,  Wondimagegn Mesfin Tesfaye,  Franziska Gassmann

Farmers' participation in the Income Stabilisation Tool: Evidence from the apple sector in Italy

Ruggiero Rippo,  Simone Cerroni

The role of family life-cycle events on persistent and transient inefficiencies in less favoured areas

Andrew P. Barnes

NOTE

A note on synthetic data for replication purposes in agricultural economics

Stefan Wimmer,  Robert Finger

Agricultural policies and food systems: Priorities for indicator development

Jonathan Brooks

Abstract: Existing indicators of agricultural protection and support were developed primarily to gauge the market and welfare effects of government policies. They have shed light on a wider range of impacts through their use in economic models and empirical analysis. The rising scale of support to agriculture globally, and continued reliance on market distorting policy instruments, make this work as important as ever. Deeper investments are nonetheless needed to address heightened concerns about the spill-over impacts of agricultural policies on the performance of food systems, in particular with respect to food security and nutrition, rural livelihoods, resource use and the environment, and global emissions. A first area for development is improved measures of policies to correct agriculture's externalities. A priority here is to develop a carbon tax equivalent of sectoral mitigation efforts. A second area is to provide a clearer delineation of government spending on private versus public goods. This would make a valuable contribution to a ‘repurposing’ agenda that seeks to identify how agricultural budgets can be spent more effectively, as well as the scope for transferring resources to wider social priorities, such as public health and climate action.

Ride the trend: Is there spread momentum profit in the US commodity markets?

Quanbiao Shang     Teresa Serra     Philip Garcia

Abstract: Some previous researchers have argued that trading strategies based on calendar spread time series momentum (STSM) can deliver significant returns (Szymanowska et al. 2014; Boons and Prado 2019), which, if true, is at odds with the efficient market hypothesis. These arguments however, do not exclude the unrealisable futures contract roll yield and are also affected by other empirical and statistical issues that may lead to misleading results. With more than 30 years of data, we investigate STSM in 22 US commodity futures markets. First, we assess whether past spread returns can predict future returns, a necessary condition for the existence of momentum. We find predictability to be very weak after correcting for the issues affecting prior research. Second, we implement STSM-based investment strategies. We compare STSM profits for individual markets and portfolios to profits generated by a simple long-only benchmark strategy that does not require any predictability. STSM does not generate returns statistically different from the benchmark trading strategy, with both strategies generating very low or negative returns. For the momentum to outperform the benchmark strategy, predictability should be three times larger than observed from real data, but would entail substantial downside risk. In sum, the empirical evidence indicates that returns from STSM-type strategies are illusive for the commodities and period studied. Our results strongly suggest that inclusion of unrealisable roll yield generates the illusion of profitable STSM trading strategies in previous research.

Can medium-scale farms support smallholder commercialisation and improve welfare? Evidence from Nigeria

Lenis Saweda O. Liverpool-Tasie    Ahmed Salim Nuhu     Titus Awokuse     Thomas Jayne     Milu Muyanga     Adebayo Aromolaran     Adesoji Adelaja

Abstract: In spite of mounting evidence about the growth of medium-scale farms (MSFs) across Africa, there is limited empirical evidence on their impact on neighbouring small-scale farms (SSFs). We examine the relationships between MSFs and SSFs, with particular focus on the specific mechanisms driving potential spillover effects. First, we develop a theoretical model explaining two propagating mechanisms: learning effects (training) and cost effects (reduced transactions cost). An empirical application to data from Nigeria shows that SSFs with training from MSFs tend to use higher levels of modern inputs (have higher productivity), and receive higher prices and income. The results also show that purchasing inputs from MSFs reduces the costs of accessing modern inputs and is associated with higher inorganic fertiliser use by SSFs. Our results suggest that the benefits of receiving training and purchasing inputs from MSFs are particularly important for very small-scale producers, operating less than 1 hectare of land. This implies that policies which promote the efficient operation of MSFs and encourage their interaction with SSFs can be an effective mechanism for improving the productivity and welfare of smallholder farms, hence reducing their vulnerability to extreme poverty.

Utilising farm-level panel data to estimate climate change impacts and adaptation potentials

Abdul Quddoos     Klaus Salhofer     Ulrich B. Morawetz

Abstract: We combine farm accounting data with high-resolution meteorological data, and climate scenarios to estimate climate change impacts and adaptation potentials at the farm level. To do so, we adapt the seminal model of Moore and Lobell (2014) who applied panel data econometrics to data aggregated from the farm to the regional (subnational) level. We discuss and empirically investigate the advantages and challenges of applying such models to farm-level data, including issues of endogeneity of explanatory variables, heterogeneity of farm responses to weather shocks, measurement errors in meteorological variables, and aggregation bias. Empirical investigations into these issues reveal that endogeneity due to measurement errors in temperature and precipitation variables, as well as heterogeneous responses of farms toward climate change may be problematic. Moreover, depending on how data are aggregated, results differ substantially compared to farm-level analysis. Based on data from Austria and two climate scenarios (Effective Measures and High Emission) for 2040, we estimate that the profits of farms will decline, on average, by 4.4% (Effective Measures) and 10% (High Emission). Adaptation options help to considerably ameliorate the adverse situation under both scenarios. Our results reinforce the need for mitigation and adaptation to climate change.

Are agro-clusters pro-poor? Evidence from Ethiopia

Martin Paul Jr Tabe-Ojong     Guyo Godana Dureti

Abstract: Governments and development agencies increasingly promote agro-clusters as a pathway to improving smallholder incomes and ensuring inclusive rural development through mitigating production and market risks. However, there is very limited empirical evidence to support this promise. We use a large farm household survey of about 4000 smallholder farmers in Ethiopia growing cereals like teff, maize, wheat, maltbarley and sesame to examine the relationship between agro-clusters and smallholder welfare and poverty. Using instrumental variable estimators, we establish a positive association between agro-clusters, household income and per capita income. Agro-clusters are also shown to reduce poverty and poverty gaps. Our results are robust over different agro-cluster proxies and alternative estimators, such as the augmented inverse probability weighting estimator. We also show that our findings are unlikely to be driven by omitted variable bias. Moving beyond average effects and in the interest of understanding heterogeneous effects, we use quantile regressions at different income levels. We find that agro-clusters are associated with welfare gains for all households. However, the most significant gains are observed for the wealthier households. Despite this regressive association, our findings suggest that agro-clusters may be useful in making farming more profitable with significant welfare implications.

Understanding the variation in estimates of off-farm labour supply elasticities: A meta-analysis

Rakhe Balachandran     Jerrod Penn     Maria Bampasidou

Abstract: The design of rural development policies and government programmes in support of farm operations and farm households relies on precise estimates of off-farm labour supply elasticities. However, the wide variation in estimates dilutes their power to predict the magnitude of these targeted interventions. We perform a meta-analysis of estimates of off-farm labour supply elasticity to identify systematic factors that influence these estimates. A sample of 137 elasticities is obtained from 43 studies which use data ranging from 1960 to 2012. We examine theoretical assumptions, data availability and empirical specifications, and other study-specific characteristics. Controlling for potential publication bias, we estimate that the elasticity is approximately 0.64 to 0.77. Results of the analysis show that estimates are affected by modelling choices controlling for self-selection and life-cycle elements. However, we found no compelling evidence that study-specific characteristics of off-farm labour supply functions, including various measurements of labour supply, explain variation in the elasticities.

Institutional quality and the duration of agri-food trade flows

Helena Engemann     Yaghoob Jafari     Thomas Heckelei

Abstract: Recent trade disruptions and their consequences on supply chains show the importance of stable trade relations for exporters' economic planning and importers' supply security. Both instability in trading partners' economic and institutional environment and differences between them are likely to exacerbate these disruptions. We investigate the role of exporters' institutional quality (IQ) and its similarity with importers' IQ in the stability of trade links. We focus on the trade links of agri-food products exported from sub-Saharan African (SSA) countries to the European Union (EU-28) and consider three dimensions of IQ: ‘government selection, monitoring, and replacement’; ‘efficiency of policy formulation and implementation’; and ‘respect of citizens and state for institutions’. Using a discrete-time duration model, we show that the duration of SSA exports to the EU-28 increases with higher exporters' IQ and similarity of trading partners' IQ. The strongest impact of exporters' IQ is associated with ‘government selection, monitoring, and replacement’. In terms of the similarity of trading partners, ‘respect of citizens and state for institutions’ has the largest impact on trade durations. Our findings suggest that the improvement of countries' IQ may boost the stability of trade relationships. Moreover, the similarity of IQs between trading partners supports the stability of trade links and should be carefully considered when establishing new trade relations.

The (in)stability of farmer risk preferences

Robert Finger     David Wüpper     Chloe McCallum

Abstract: We test and quantify the (in)stability of farmer risk preferences, accounting for both the instability across elicitation methods and instability over time. We use repeated measurements (N = 1530) with Swiss fruit and grapevine producers over 3 years, using different risk preference elicitation methods (domain-specific self-assessment and incentivised lotteries). We find that farmers' risk preferences change considerably when measured using different methods. For example, self-reported risk preference and findings from a Holt and Laury lottery correlate only weakly (correlation coefficients range from 0.06 to 0.23). Moreover, we also find that risk preferences vary considerably over time, that is, applying the same elicitation method to the same farmer in a different point in time results in different risk preference estimates. Our results show self-reported risk preferences are moderately correlated (correlation coefficients range from 0.42 to 0.55) from one year to another. Finally, we find experiencing crop damages due to climate extremes and pests is associated with farmers becoming more risk tolerant over time in specific domains.

Mobilising the public to fight poverty using anti-poverty labels in online food markets: Evidence from a real experimental auction

Yu Jiang    H. Holly Wang    Shaosheng Jin

Abstract: In an emerging economy like China where the domestic income inequality has dramatically increased between middle-class urban consumers and poor rural farmers, food grown by poor farmers with poverty alleviation labels may receive price premiums from consumers with multiple incentives. To reveal consumers' willingness-to-pay (WTP) for anti-poverty labelled food, we implement a non-hypothetical Becker–DeGroot–Marschak auction online experiment for apples with real shoppers. Results show that consumers are willing to pay 3.66 RMB extra for each kilogram of apples with anti-poverty labels, indicating the opportunities for using voluntary public food consumption to supplement the government's anti-poverty responsibilities. Consumers who are more empathic, who believe that anti-poverty products have higher quality, who have donated money within the past year, and who are not involve with anti-poverty related production or selling processes are willing to pay more. Additionally, three different information treatments (a beneficiary description, an appreciation certificate and a government promotion document) were found to increase consumers' WTP for anti-poverty products. Treatment effects are different among consumers with different demographic characters and perspectives about the anti-poverty label. Lastly, anti-poverty labels can attract consumers for trial purchase but are not sufficient to lead consumers to make repeat purchases.

Are farmers ‘efficient but poor’? The impact of crop choices on technical efficiency and poverty in Nigeria

Chisom Lotanna Ubabukoh     Katsushi S. Imai

Abstract: We test the ‘efficient-but-poor’ hypothesis by estimating the determinants of smallholders' choice over cash or food crops and whether their crop choice affects technical efficiency and poverty using the national household panel data in Nigeria. We employ the stochastic frontier analyses correcting for sample selection about farmers' crop choice. Our results indicate that smallholders are generally efficient in their resource allocations. A treatment effects model is employed to estimate farmers' crop choice in the first stage and the impact of their choices on technical efficiency and poverty outcomes in the second stage. The results show that farmers' access to free inputs, non-farm income and the use of seeds from the previous growing season are important determinants of crop choice. The adoption of cash crops by food-crop producing households will not generally reduce poverty, although it will improve technical efficiency marginally. However, if cash crops are commercialised, poverty tends to decline.

Predator or prey? Effects of farm growth on neighbouring farms

Franziska Appel     Alfons Balmann

Abstract: We provide explorative insights on how farms which manage strong and successful growth affect farms in their neighbourhoods through spatial competition for land. The study is based on an exploratory analysis of repeated framed experiments within the business game FarmAgriPoliS (Appel & Balmann, Ecological Complexity, 40, 2019). In particular, we analyse the spatial influences of different behavioural clusters of farm managers. Our analysis finds that farms which manage strong growth substantially affect the development of farms in a spatial neighbourhood of some 10 km. Although the influence on the neighbourhood decreases with distance, the functional correlations of farm growth as well as exits are neither linear nor exponential, but eventually rather wave-like. We further discuss the spatial interdependence of farms and the related overlaps of the predator–prey phenomenon with the phenomena of farms' path dependency and agricultural structural change. We conclude that along with farmers' strategies and their abilities, the characteristics of their neighbours and the distances between neighbouring farms also determine who is ‘predator’ and who is ‘prey’.

Input subsidies and crop diversity on family farms in Burkina Faso

Sibbir Ahmad    Melinda Smale     Veronique Theriault    Eugenie Maiga

Abstract: Since their independence, many countries in sub-Saharan Africa have used input subsidies to increase agricultural productivity and improve food security. We analyse the effects of both a fertiliser and a seed subsidy on farming households' land allocation among crops and crop diversity in Burkina Faso. Although previous studies investigated either the impact of a fertiliser or a seed subsidy on targeted crops, few examined the effects of both subsidies combined. Applying a correlated random-effects model with a control function approach to nationally representative, 2-year panel data collected from farming households, we find that those with access to the fertiliser subsidy allocate more land to the crops it targets (rice, maize and cotton) than non-targeted crops. Focusing on a minor crop with key agronomic and nutritional attributes, we conclude that land allocation to cowpea as the primary crop and intercrop declined with the fertiliser subsidy. The fertiliser subsidy also negatively affects crop diversity. However, we find that the cowpea seed subsidy offsets the bias of fertiliser subsidy toward fertiliser-targeted crops and enhances diversity.

Early growing season weather variation, expectation formation and agricultural land allocation decisions in Ethiopia

Musa Hasen Ahmed    Wondimagegn Mesfin Tesfaye     Franziska Gassmann

Abstract: Using unique crop-specific data gathered over 7 years, we study if and how maize-producing farmers in Ethiopia adjust their land allocation decisions in response to pre-planting-season weather variations. We show that farmers adjust their land allocation decisions in response to increased temperatures early in the growing season. In addition to quantifying a substantial adaptation margin that has not been documented before, our study also reveals the presence of a weather variation-induced expansion of maize production into areas that are less suitable for maize cultivation.

Farmers' participation in the Income Stabilisation Tool: Evidence from the apple sector in Italy

Ruggiero Rippo     Simone Cerroni

Abstract: The Income Stabilisation Tool (IST), which was recently added to the European Common Agricultural Policy's risk management toolkit, is a mutual fund that aims at stabilising farmers' income. We investigate the drivers of farmers' participation in an IST for the apple sector in the Autonomous Province of Trento in Italy, which is the only region that has operationalised the IST in the European Union. Our analysis is based on a theoretical framework based on the Unified Theory of Use and Acceptance of Technology. Using a three-year panel dataset of 3268 farm households, we estimated a logit model with the Mundlak–Chamberlain procedure. Our results show that higher crop production specialisation, associated with greater risk exposure, favours participation in the IST. Similarly, previous experience with mutual funds increases the acceptance of the IST. The analysis also provides evidence of how the new tool interacts with existing on-farm protection strategies, leading to a discussion of the presence of adverse and advantageous selection effects. Our paper sheds light on farmers' acceptance of newly implemented sector-specific ISTs and generates better knowledge and understanding of lock-ins and levers that influence participation in such schemes, which are relevant to other EU regions or member states that are considering the introduction of ISTs.

The role of family life-cycle events on persistent and transient inefficiencies in less favoured areas

Andrew P. Barnes

Abstract: Family farms dominate less favoured areas (LFAs) within Europe, and family life-cycle conditions, such as succession and retirement, affects how these farms adapt to changing circumstances. Past studies of on-farm technical efficiency have not directly addressed these conditions, but they may explain why some farms are more efficient than others, especially as the farm family model dominates most farming systems. Motivated by the UK's withdrawal from the EU and the debate around establishing replacement support policies, we apply a multi-step model to measure both transient and persistent inefficiencies using a panel of LFA cattle and sheep farms in Scotland over the period 2003–2020. We find a greater prevalence of persistent compared to transient inefficiency, which suggests that structural problems still exist. Farms with planned succession are found to have higher persistent efficiencies, whereas farmers nearing retirement have lower levels. Other factors, such as dependence on subsidy, off-farm activity and classification as severely disadvantaged tend to compound these lower efficiencies. We argue that life-cycle conditions should not be ignored in studies of farm technical efficiency. Within the scope of framing a new agricultural policy for UK administrations, these results inform the debate on support for LFAs, as well as the promotion of support towards generational renewal to ease transition across farm family life-cycle events.

A note on synthetic data for replication purposes in agricultural economics

Stefan Wimmer     Robert Finger

Abstract: Empirical studies in agricultural economics usually involve policy implications. In many cases, such studies rely on proprietary or confidential data that cannot be published along with the article, challenging the replicability and credibility of the results. To overcome this problem, the use of synthetic data—that is, data that do not contain a single unit of the original data—has been proposed. In this note, we illustrate the utility of synthetic data generation methods for replication purposes using a range of methods from agricultural production analysis. More specifically, we compare input elasticities and technical efficiency scores based on different farm-level production data between original data and synthetic data. We generate synthetic data using a non-parametric method of classification and regression trees (CART) and parametric linear regressions. We find synthetic data result in elasticities and technical efficiency distributions that are very similar to the original data, especially when generated with CART, and conclude with implications for the research community.

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编辑：秦运兰

审核：龙文进