Collective livestock research for sustainable disease management in Mali and Burkina Faso

An international multi-disciplinary team of scientists, led by the International Livestock Research Institute (ILRI), tackled the problem of bovine trypanosomosis and the development of drug resistance in West Africa, inter alia, by the promotion of rational drug use (RDU) principles. These principles had been brought to farmers by practical training and by the provision of information leaflets. This study aimed to evaluate the impact of RDU training at smallholder level with respect to advances in farmers' knowledge and farm productivity before research outputs could be scaled up. Therefore, 508 cattle farmers attended a disease-specific knowledge test and provided information about farm production. Results show that farmers who participated in the training are more likely to identify signs and causes of the disease and to correctly administer drugs. Allocating scores to each question in the knowledge tests and scrutinizing the differences between trained and untrained farmers by matching procedures shows that participating farmers reach higher scores in all knowledge categories. Moreover, the acquisition of additional knowledge and the application of improved control strategies significantly increase farm performance. Additionally, an allocative effect was identified since trypanocide expenditures were saved by less expensive inputs.     

Testing the null hypothesis of no regime switching with an application to GDP growth rates

This paper presents tests for the null hypothesis of no regime switching in Hamilton’s (Econometrica 57:357–384, 1989) regime switching model. The test procedures exploit similarities between regime switching models, autoregressions with measurement errors, and finite mixture models. The proposed tests are computationally simple and, contrary to likelihood based tests, have a standard distribution under the null. When the methodology is applied to US GDP growth rates, no strong evidence of regime switching is found. I thank Don Andrews, Peter Phillips, Yuichi Kitamura, Anat Bracha, Patrik Guggenberger, Orit Whiteman and three anonymous referees for useful comments and suggestions.     

新环保法实施增大了企业的技术创新投入吗？——基于PSM-DID方法的研究

以2012—2017年A股上市公司为样本,借助双重差分倾向得分匹配法（PSM-DID）研究了新环保法实施这一外生性事件对企业技术创新投入的影响。结果显示,新环保法实施后受影响企业的技术创新投入有所增加,但结果并不显著。进一步探究其原因,发现除新环保法影响可能存在的时滞性特征以外,企业并没有在新环保法实施环境下对企业的资本结构、治理结构和激励方案等影响企业技术创新的重大方面做出及时调整,导致环保法的强制性作用无法快速、有效地影响企业的技术创新。     

The effects of exports on facility environmental performance: Evidence from a matching approach

This paper employs matching techniques to investigate the effects of facility export status on environmental performance. Using facility-level criteria air emission data in the US manufacturing industry, we find the industry-specific effects of export status on emission intensity, measured by emissions per value of sale. In some industries, there is consistent and robust evidence supporting the superior environmental performance of exporters relative to non-exporters in terms of emission intensity for all criteria air pollutants tracked. In other industries, we find weak evidence that exporters appear to have a higher emission intensity than non-exporters. This industrial heterogeneity in the effects of exporting on the environment is closely related to industrial characteristics including pollution abatement capital expenditure, trade costs, capital intensity and others.     

Entrepreneurial innovativeness and growth ambitions in thick vs. thin regional innovation systems

Research in economic geography has paid increasing attention to regional innovation systems (RISs) as a potential vehicle for growth and development. Yet despite an increasing amount of research studying RISs in particular and economic regions in general, we have limited knowledge about their influence on entrepreneurs and entrepreneurship. We respond to this knowledge gap and study if entrepreneurs’ localization in thick vs. thin RISs affects their innovativeness and growth ambitions. Thick RISs are predominately urbanized spaces that include organizations of higher-level education, R&D intensive milieus, and an ample industry sector, while thin RISs to a lesser degree encompass these features. Empirically, we analyse 870–917 entrepreneurial firms in Agder of Southern Norway. Based on trade and labour markets, as defined by the EU’s classification of local administrative units (LAU1), we identify two thick and six thin RISs in Agder. Econometric analyses show that entrepreneurs located in thick RISs are more innovative than entrepreneurs located in thin RISs, but there are no significant differences concerning entrepreneurs’ growth ambitions. In light of our findings, we discuss the potential agency role played by entrepreneurial firms at a micro level on path dependent features of RISs at a macro level.     

Local poverty reduction in Chile and Mexico: The role of food manufacturing growth

This paper analyzes the relationship between local poverty and food manufacturing growth in Chile and Mexico using propensity score matching, differences in differences and spatial econometrics methods. We focus on food manufacturing as a sector with a number of characteristics that make it potentially pro-poor, and whose incentives for spatial distribution may either strengthen or dampen its poverty reduction potential. The overall results indicate growth in food manufacturing employment contributes to local poverty reduction.     

Is There Persistence in the Impact of Emergency Food Aid? Evidence on Consumption, Food Security, and Assets in Rural Ethiopia

We identify the impact of emergency food aid programs after the 2002 drought in rural Ethiopia on future welfare. Based on a difference-in-differences matching estimator, participation in food-for-work increases growth in total consumption and food consumption eighteen months after the drought. Separately, receiving free food raises growth in food consumption, but, surprisingly, negatively impacts food security. Food-for-work benefited households in the middle and upper tail of the consumption distribution, while the better-targeted free food program benefited the poorest. Evidence suggests these impacts demonstrate accumulated and persistent effects of food aid received in the first twelve months after the drought.     

区域产业发展视角的农业综合开发影响评估——基于对蔬菜产业的干预效应分析

【目的】通过定量方法准确评估农业综合开发对区域优势产业发展的影响有重要意义。【方法】从农业综合开发对蔬菜产业的项目干预效应入手,以县级为单位,将当年农业综合开发项目扶持内容包括蔬菜产业的县级单位划分为干预组,其他为控制组。采用可以有效解决样品选择偏差的倾向得分匹配方法,通过引入协变量、平衡检验、匹配等步骤,在控制组中找到与干预组成员单位特征相似的成员,构建反事实研究框架。【结果】结果得出,项目干预组比控制组区域的蔬菜播种面积占比高出1~3个百分点,说明农业综合开发项目对蔬菜产业的扶持对蔬菜播种面积的扩大有促进作用,利于蔬菜产业壮大。通过协变量影响力分析得出,地区的蔬菜生产优势是最重要的影响因素,从侧面证明了农业综合开发项目的扶持方向紧跟区域优势的政策宗旨。【结论】可见,通过有方向性的农业综合开发项目实施扶持特定产业对促进区域优势产业发展和实现农业结构优化是有效的。     

What is the benefit of membership in farm producer organizations? The case of coffee producers in Peru

Empirical evidence of the benefit of farm producer organizations (FPOs) in the developing world is mounting. There is, however, no work in South America on the relationship between FPO membership and farm-level performance. We address the gap by estimating the treatment effect of FPO membership with respect to three outcomes: quantity produced, quantity sold, and price received. The empirical application focuses on the Peruvian coffee sector, where FPOs may have played an important role during the recent price crisis. A sample of approximately 9,000 survey responses from Peruvian coffee producers during the 2015–19 period is used in the analysis. Results show a positive treatment effect of FPO membership on all three farm-level outcomes. Compared to non-FPO members, FPO members produced 120–295 kg/ha more, sold 118–296 kg/ha more, and received 0.42–1.53 PEN/kg more. We also find evidence of heterogeneity in the estimated effect of FPO membership across time, farm size, and membership probability. The findings yield novel implications in terms of policy support for FPOs.     

Tuition fees and social segregation: lessons from a natural experiment at the University of Paris 9-Dauphine

Using a natural experiment, a sharp rise in tuition fees in some of the programmes at the University of Paris 9-Dauphine, we study the impact of tuition fees on students’ pathways, and outcomes. We apply an optimal matching method to the national database of students’ registrations (SISE) to define a typology of pathways. We then use a nonordered multinomial logit model to evaluate the impact of the rise in tuition fees on the types of pathways selected by the university. We show that there is a significant impact on these pathways. The increase in tuition fees reduces geographic and social mobility, thereby accentuating the phenomena of social segregation. Furthermore, contrary to what some of the studies assert, the rise does not appear to encourage greater effort: we find no impact on the graduation success rate.