Di Zeng

Measuring Farm and Market Level Economic Impacts of Improved Maize Production Technologies in Ethiopia: Evidence from Panel Data

While it is often recognised that agricultural technology adoption decisions are intertwined and best characterised by multivariate models, typical approaches to examining adoption and impacts of agricultural technology have focused on single technology adoption choice and ignored interdependence among technologies. We examine farm†and market†level impacts of multiple technology adoption choices using comprehensive household survey data collected in 2010/11 and 2012/13 in Ethiopia. Economic surplus analysis combined with panel data switching endogenous regression models are used to compute the supply shift parameter (K†shift parameter), while at the same time controlling for the endogeneity inherent in agricultural technology adoption among farmers. We find that our improved technology set choices have significant impacts on farm†level maize yield and maize production costs, where the greatest effect appears to be generated when various technologies are combined. The change in maize yield and production costs results in an average 26.4% cost reduction per kilogram of maize output (the K†shift parameter). This increases the producer and consumer surpluses by US

A closer look at the rural-urban health disparities: Insights from four major diseases in the Commonwealth of Virginia.

140 and US

Factors affecting Chinese broiler farmers’ main preventive practices in response to highly pathogenic avian influenza

105 million per annum, respectively. These changes in economic surplus help to reduce the number of poor people by an estimated 788 thousand per year. We conclude that deliberate extension efforts and other policies that encourage integration of technologies are important for maize technologies to yield their full potential at both farm and market levels.

Land ownership and technology adoption revisited : improved maize varieties in Ethiopia

Health disparities are increasingly recorded in literature, but are much less understood in a rural-urban context. This study help bridges this gap through investigation of four major diseases in the Commonwealth of Virginia: cancer, stroke, cardiovascular disease and chronic obstructive pulmonary disease. We utilize a unique inpatient hospital discharge billing dataset, and construct average patient counts at ZIP-code level over 2006-2008 where covariates from alternative sources are merged (806 ZIP-code areas, 190 urban, 616 rural). Count data regressions are first fitted to identify possible regional-level factors that affect disease incidences. A system of equations with rural-urban specification are then estimated via seemingly unrelated regression techniques to account for possible associations among these diseases and correlations of errors, which is followed by disease-specific nonlinear Blinder-Oaxaca decompositions that compare the respective explanatory powers of observed characteristics and unobserved mechanisms. Results suggest that regional-level factors are significantly correlated with health outcomes in both rural and urban areas. The unknown mechanisms behind these linkages are different between rural and urban areas, and explain even larger proportions of the observed disparities. These findings confirm the role of regional-level factors in generating rural-urban health disparities, and call for further investigations of the causal mechanisms of such disparities that remain largely unknown.

Neighbourhood convenience stores and childhood weight outcomes: an instrumental variable approach

Preventive practices are highly important in response to highly pathogenic avian influenza (HPAI). As biosecurity guidelines, HPAI vaccination, antiviral medication, farm cleaning and disinfection jointly focus on mitigating the risk of infectious pathogen spread, yet much less is known about the association between broiler farmers socio-economic characteristics and their adoption decision of these preventive practices. The current study aims to bridge this gap using a nationally representative household survey of 331 Chinese chicken farm owners, among whom the practices are far from fully adopted (only 58% of the farmers adopt all four types). Discrete choice modeling reveals that farmers gender, age, education, perceived disease impact, farming experience, breeding density, chicken feed conversion ratio, chicken daily weight gain, available service, and subsidy are playing important roles in adoption decision making. Moreover, farmers with husbandry and veterinary knowledge, longer farming experience and lower feed conversion ratios tend to adopt all preventive practices, whereas farmers with larger proportions of income coming from chicken farming tend not to.

Middle school transition and body weight outcomes: Evidence from Arkansas Public Schoolchildren.

Highlights • We study whether land rental discourages improved crop variety adoption.• We show in theory that cash-renters are indifferent, but sharecroppers are encouraged.• Empirical results from Ethiopian maize farmers support the above hypotheses.• Results imply improvements in land rental markets can improve farmers’ welfare.

Ex post impacts of improved maize varieties on poverty in rural Ethiopia

ABSTRACT The association between the commercial food environment and childhood obesity is increasingly assessed in the literature, but little is known about the role of convenience stores, an important food retail format worldwide. This study helps bridge the gap using individual-level data containing measured body mass index (BMI) for public schoolchildren and geo-coded residence and store locations in Arkansas, United States. The distance from residence to the nearest highway is employed to instrument neighbourhood convenience store exposure, while controlling for possible confounding effects of other food stores. We find that exposure to at least one convenience store exposure is associated with a BMI z-score increase of 0.162 SD, and exposure to each additional convenience store is associated with a BMI increase of 0.071 SD. There is no evidence for a larger association among children from low-income families or those with limited access to healthy foods.

Agricultural technology adoption and child nutrition enhancement: improved maize varieties in rural Ethiopia

There is evidence that middle school transition adversely affects educational and psychological outcomes of pre-teen children, but little is known about the impacts of middle school transition on other aspects of health. In this article, we estimate the impact of middle school transition on the body mass index (BMI) of public schoolchildren in Arkansas, United States. Using an instrumental variable approach, we find that middle school transition in grade 6 led to a moderate decrease of 0.04 standard deviations in BMI z-scores for all students. Analysis by subsample indicated that this result was driven by boys (0.06-0.07 standard deviations) and especially by non-minority boys (0.09 standard deviations). We speculate that the changing levels of physical activities associated with middle school transition provide the most reasonable explanation for this result.