Agriculture and climate change in global scenarios: why don't the models agree

Agriculture is unique among economic sectors in the nature of impacts from climate change. The production activity that transforms inputs into agricultural outputs involves direct use of weather inputs (temperature, solar radiation available to the plant, and precipitation). Previous studies of the impacts of climate change on agriculture have reported substantial differences in outcomes such as prices, production, and trade arising from differences in model inputs and model specification. This article presents climate change results and underlying determinants from a model comparison exercise with 10 of the leading global economic models that include significant representation of agriculture. By harmonizing key drivers that include climate change effects, differences in model outcomes were reduced. The particular choice of climate change drivers for this comparison activity results in large and negative productivity effects. All models respond with higher prices. Producer behavior differs by model with some emphasizing area response and others yield response. Demand response is least important. The differences reflect both differences in model specification and perspectives on the future. The results from this study highlight the need to more fully compare the deep model parameters, to generate a call for a combination of econometric and validation studies to narrow the degree of uncertainty and variability in these parameters and to move to Monte Carlo type simulations to better map the contours of economic uncertainty.     

The Impact of Seed Policy Reforms and Intellectual Property Rights on Crop Productivity in India

The growth of private investment in developing‐country agriculture, new advances in the biological sciences, and rapid integration of developing countries into the global trading system has heightened interest in the topic of seed market and intellectual property rights’ (IPRs) policies among public policy‐makers, corporate decision‐makers and other actors in the agricultural sector. But there are still unanswered questions about whether emerging and evolving seed policy reforms and IPR regimes in developing countries will contribute to increasing crop productivity and improving food security. This paper attempts to answer some of these questions by focusing specifically on the case of India, the regional leader in implementing seed policy reforms and IPRs in agriculture. Findings indicate that maize and pearl millet yields grew significantly during the last two decades due partly to the combination of (1) public policies that encouraged private investment in India’s seed industry during the 1980s, and (2) biological IPRs conferred by hybridisation that conveniently married the private sector’s need for appropriability with the nation’s need for productivity growth. Although past lessons are not an indication of future success, this convergence of policy solutions and technology opportunities can be replicated for other crops that are vital to India’s food security.     

Competition,Loan Rates,and Information Dispersion in Nonprofit and For‐Profit Microcredit Markets

We describe the competitive environment of microcredit markets globally and we study the effects of competition on loan rates of microfinance institutions (MFIs). We use a new database from rating agencies, covering 379 for‐profit and nonprofit MFIs in 67 countries over 2002–2008. Controlling for interest rate ceilings and other country‐specific factors, we first find that nonprofits are relatively insensitive to industry‐wide concentration changes, while for‐profits charge significantly lower rates in less concentrated markets. Second, we find spillover effects between the for‐profit and nonprofit segments. Third, we show that the effects of concentration are consistent with an information dispersion mechanism.     

莱索托地区北京一号全色影像几何校正方法研究

研究目的：确定莱索托地区北京一号全色影像几何校正方法。研究方法：基于线阵推扫式模型和投影变换模型的几何校正方法,采用真实的莱索托境内平地、高山地两景北京一号全色影像进行试验。研究结果：基于投影变换模型的莱索托地区北京一号全色影像几何校正方法比基于线阵推扫式模型的几何校正方法具有相当或更高的精度。研究结论：投影变换模型可用于莱索托地区土地利用遥感影像图的制作。     

Technological and policy options for sustainable agricultural intensification in eastern Uganda

This article presents a bio‐economic household model, which has been developed to assess the potential impacts of agricultural intensification efforts on economic and ecological indicators in eastern Uganda. A study region in the Lake Victoria Crescent was selected with comparative advantages for intensive agricultural production: high agricultural potential, high market access, and high population density. However, current production is characterized by low input–output systems revealing a discrepancy between development opportunities and actual development outcomes. Based on a farmer participatory research approach, production methods were introduced in the study region aimed at fostering sustainable agricultural development. Data from two community surveys, two comprehensive household and plot level surveys, and farm‐trial data were used to develop and calibrate bio‐economic models for four representative household types. Model scenarios reveal that farm households in eastern Uganda would not pursue sustainable intensification under current socio‐economic conditions. The market environment has to be improved substantially, i.e., transaction and transportation costs have to be reduced, innovative credit schemes for smallholders have to be introduced, and alternative forms of labor acquisition have to be promoted, to provide sufficient economic incentives for the adoption of environmentally sound production methods. In addition, agricultural service provision needs to be reformed and more agricultural research is needed for new and better‐targeted technologies.     

基于CSIX-L1接口协议的通用交换芯片设计

作为美国商事交易的重要成文法,《美国统一商法典》(UCC)全面规定了商事合同中买方违约时,卖方有权采取的包括持贷不交和再出售等8种补救措施。这些措施体现了美国合同立法中的严格责任和补偿原则的立法精神。UCC 的立法规定,对我国涉外经济合同立法有所启示和借鉴。同时在中美贸易频繁化和中国成为WTO 成员的背景下,研究UCC 的相关规定,对保护我方当事人的商事利益也有实际价值。     

Macroeconomic Sources of Risk in the Term Structure

We develop a new way of modeling time variation in term premia, based on the stochastic discount factor model of asset pricing. The joint distribution of excess U.S. bond returns of different maturity and the observable fundamental macroeconomic factors is modeled using multivariate GARCH with conditional covariances in the mean to capture the term premia. By testing the assumption of no arbitrage we derive a specification test of our model. We estimate the contribution made to the term premia at different maturities through real and nominal sources of risk. From the estimated term premia we recover the term structure of interest rates and examine how it varies through time. Finally, we examine whether the reported failures of the rational expectations hypothesis can be attributed to an omitted time-varying term premium.     

Efficiency in wine grape production: comparing long‐established and newly developed regions of South Africa

Efficiency, partly based on technology, is central to international competitiveness. This article applies a stochastic frontier inefficiency model to a panel of 77 wine grape farms in South Africa between 2005 and 2015 and allows the comparison of efficiency levels for the old established wine regions with those of newer entrants. Thus, we investigate whether experience plus first choice of location matters more than the follower's advantage of newer technology. In all regions, a greater share of permanent labor and increased supervision raised efficiency, while more inorganic fertilizer and less irrigation has the opposite effect. Innovations in trellising had insignificant effects (except in the old regions) but not replacing old vines reduced efficiency. However, a higher proportion of red varietals also lowered efficiency in the old regions due to a fall in the price of red wine as these farmers continued to concentrate on quality reds. The new regions compensated for falling prices by increasing crop size with irrigation and fertilizer and extending the area planted, but with less concern for quality. This appears to be more successful in efficiency terms, but as international demand for quality wine increases it may be a poor long‐term strategy.