Lovell S. Jarvis

Predicting the Diffusion of Improved Pastures in Uruguay

Research suggests the logistic curve is the characteristic diffusion path for new technologies. Econometric analysis of fertilized grass-legume pastures in Uruguay indicated that their diffusion during the first years following introduction also followed a logistic path. Some departure from a simple logistic shape was explained by including beef and fertilizer prices within the diffusion framework. Both the rate and limit of diffusion were positively related to changes in the technologys profitability, but the estimated price elasticity of each was low. Extrapolation predicted that a ceiling equal to 12% of Uruguayan pasture area would be reached in 1980.

Climate-smart agriculture global research agenda: scientific basis for action

BackgroundClimate-smart agriculture (CSA) addresses the challenge of meeting the growing demand for food, fibre and fuel, despite the changing climate and fewer opportunities for agricultural expansion on additional lands. CSA focuses on contributing to economic development, poverty reduction and food security; maintaining and enhancing the productivity and resilience of natural and agricultural ecosystem functions, thus building natural capital; and reducing trade-offs involved in meeting these goals. Current gaps in knowledge, work within CSA, and agendas for interdisciplinary research and science-based actions identified at the 2013 Global Science Conference on Climate-Smart Agriculture (Davis, CA, USA) are described here within three themes: (1) farm and food systems, (2) landscape and regional issues and (3) institutional and policy aspects. The first two themes comprise crop physiology and genetics, mitigation and adaptation for livestock and agriculture, barriers to adoption of CSA practices, climate risk management and energy and biofuels (theme 1); and modelling adaptation and uncertainty, achieving multifunctionality, food and fishery systems, forest biodiversity and ecosystem services, rural migration from climate change and metrics (theme 2). Theme 3 comprises designing research that bridges disciplines, integrating stakeholder input to directly link science, action and governance.OutcomesIn addition to interdisciplinary research among these themes, imperatives include developing (1) models that include adaptation and transformation at either the farm or landscape level; (2) capacity approaches to examine multifunctional solutions for agronomic, ecological and socioeconomic challenges; (3) scenarios that are validated by direct evidence and metrics to support behaviours that foster resilience and natural capital; (4) reductions in the risk that can present formidable barriers for farmers during adoption of new technology and practices; and (5) an understanding of how climate affects the rural labour force, land tenure and cultural integrity, and thus the stability of food production. Effective work in CSA will involve stakeholders, address governance issues, examine uncertainties, incorporate social benefits with technological change, and establish climate finance within a green development framework. Here, the socioecological approach is intended to reduce development controversies associated with CSA and to identify technologies, policies and approaches leading to sustainable food production and consumption patterns in a changing climate.

Stochastic Rangeland Use under Capital Constraints

The stocking density on Kazakhstans extensive rangelands is well below traditional levels. To analyze dynamic flock performance, we develop a stochastic dynamic programming model for livestock systems with stochastic forage production. The model contains continuous five state and 12 control variables, allowing improved characterization of the biophysical relationships and economic tradeoffs inherent in such systems. Most Kazakhstan herders have restricted access to capital. The model indicates that the cost of capital strongly affects flock size and productivity. We conclude that capital constraints are important to explaining the current low stocking density. Improving capital markets in rural areas warrants policy attention.

Food consumption in Mexico: demographic and economic effects.

Disaggregated demand analysis is beginning to receive increased importance in food policies for developing countries. Using household data from the 1977 Mexican Income and Expenditure Household Survey, the authors estimate the income and demographic effects on expenditures for 9 aggregate food categories. In addition, they use a probit model to explore the effect of these variables on the purchase decision for 5 high protein supplying goods. The results indicate that demographic variables, as well as income, have important effects in determining food expenditures. The authors analyze these effects and indicate the role they might play in food policy programs such as PRONAL, the National Food Programme.

The Impact of Chilean Fruit Sector Development on Female Employment and Household Income

Modern fruit sector development in Chile led to agricultural employment for women, though usually only as temporary workers and often at a piece rate. Nonetheless, fruit sector employment offered women access to income and personal fulfillment previously lacking. The authors link the fruit sector to improving female and family economic welfare in rural Chile and changing gender relations. Using a unique longitudinal data set, they examine womens decisions regarding labor force participation and employment, their earnings and contributions to household income, and their attitudes toward employment to understand how new opportunities are changing women, their households, and the rural sector.

Measuring Progress on the Control of Porcine Reproductive and Respiratory Syndrome (PRRS) at a Regional Level: The Minnesota N212 Regional Control Project (Rcp) as a Working Example

Due to the highly transmissible nature of porcine reproductive and respiratory syndrome (PRRS), implementation of regional programs to control the disease may be critical. Because PRRS is not reported in the US, numerous voluntary regional control projects (RCPs) have been established. However, the effect of RCPs on PRRS control has not been assessed yet. This study aims to quantify the extent to which RCPs contribute to PRRS control by proposing a methodological framework to evaluate the progress of RCPs. Information collected between July 2012 and June 2015 from the Minnesota Voluntary Regional PRRS Elimination Project (RCP-N212) was used. Demography of premises (e.g. composition of farms with sows = SS and without sows = NSS) was assessed by a repeated analysis of variance. By using general linear mixed-effects models, active participation of farms enrolled in the RCP-N212, defined as the decision to share (or not to share) PRRS status, was evaluated and used as a predictor, along with other variables, to assess the PRRS trend over time. Additionally, spatial and temporal patterns of farmers’ participation and the disease dynamics were investigated. The number of farms enrolled in RCP-N212 and its geographical coverage increased, but the proportion of SS and NSS did not vary significantly over time. A significant increasing (p<0.001) trend in farmers’ decision to share PRRS status was observed, but with NSS producers less willing to report and a large variability between counties. The incidence of PRRS significantly (p<0.001) decreased, showing a negative correlation between degree of participation and occurrence of PRRS (p<0.001) and a positive correlation with farm density at the county level (p = 0.02). Despite a noted decrease in PRRS, significant spatio-temporal patterns of incidence of the disease over 3-weeks and 3-kms during the entire study period were identified. This study established a systematic approach to quantify the effect of RCPs on PRRS control. Despite an increase in number of farms enrolled in the RCP-N212, active participation is not ensured. By evaluating the effect of participation on the occurrence of PRRS, the value of sharing information among producers may be demonstrated, in turn justifying the existence of RCPs.

A Selective Review of the Economic Analysis of Animal Health Management

Economists and veterinarians use similar approaches to analyse animal health threats, but veterinarians are concerned primarily with providing practical guidelines to peers and/or policy†makers, while economists focus more on understanding the benefits to society as a whole and often provide only general guidelines to policy†makers and little specific direction to practicing veterinarians. Despite the benefits of working together, differences in perspective and analytical approach often cause economists and veterinarians to struggle in dialogue and to lose some of the mutual gains that could be achieved through collaboration. This article discusses the use of economics in animal health management, identifies several useful literature reviews, and analyses a number of recent studies to explore the advantages and disadvantages of different conceptual and methodological approaches.

How Brazil Transferred Billions to Foreign Coffee Importers: The International Coffee Agreement, Rent Seeking and Export Tax Rebates

Rent seeking is well known, but empirical evidence of its effects is relatively rare. This paper analyzes the how domestic and international rent seeking caused Brazil to provide coffee export tax rebates that transferred foreign exchange to coffee importers. Although Brazil was the worlds largest exporter, it began to pay export tax rebates to selected coffee importers in 1965 and, by 1988, had paid rebates totaling

Using machine learning to predict swine movements within a regional program to improve control of infectious diseases in the US

8 billion. Brazil explained these rebates as a mechanism to price discriminate among importers and expand exports within the context of the export quota imposed by the International Coffee Agreement. We show this explanation was invalid during most of the period. The net price fell for those who received rebates, causing Brazil to effectively transfer approximately

Wildlife conservation, labor supply and time values in rural Botswana

3 billion to foreign importers. The effects of the rebate policy were never recognized in Brazil, hidden largely by the complex nature of government intervention in the coffee sector.