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on Agricultural Economics |
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Issue of 2014‒02‒02
twenty-two papers chosen by |
| By: | Alston, Julian M.; Pardey, Philip G. |
| Keywords: | Agricultural and Food Policy, Food Security and Poverty, |
| Date: | 2014–01–07 |
| URL: | http://d.repec.org/n?u=RePEc:ags:umaesp:162413&r=agr |
| By: | Mason, Nicole M.; Jayne, T.S.; Mofya-Mukuka, Rhoda |
| Abstract: | Nearly three decades after the initiation of agricultural market reforms in Sub-Saharan Africa (SSA), subsidies for fertilizer and seed are once again the cornerstone of many SSA governments’ agricultural development and poverty reduction strategies. Zambia is a prime example. In the last decade, the Government of Republic of Zambia (GRZ) has devoted a considerable share of its agricultural budget to input subsidies. Between 2004 and 2011, spending on the Farmer Input Support Programme (FISP) accounted for an average of 30% of total GRZ agricultural sector spending, and 47% of GRZ agricultural sector Poverty Reduction Programme spending. Through FISP, GRZ provides beneficiary farmers with subsidized fertilizer and hybrid maize seed. |
| Keywords: | Agricultural and Food Policy, Crop Production/Industries, Food Security and Poverty, Political Economy, |
| Date: | 2013–08 |
| URL: | http://d.repec.org/n?u=RePEc:ags:midcwp:162438&r=agr |
| By: | Haggblade, Steven; Diallo, Boubacar; Staatz, John; Theriault, Veronique; Traoré, Abdramane |
| Abstract: | Food and social safety nets have a history as long as human civilization. In hunter gatherer societies, food sharing is pervasive. Group members who prove unlucky in the short run, hunting or foraging, receive food from other households in anticipation of reciprocal consideration at a later time (Smith 1988). With the emergence of the first large sedentary civilizations in the Middle East, administrative systems developed specifically around food storage and distribution. The ancient Egyptians, for example, stored food in public warehouses for distribution in times of famine. |
| Keywords: | Agricultural and Food Policy, Food Consumption/Nutrition/Food Safety, |
| Date: | 2013–10 |
| URL: | http://d.repec.org/n?u=RePEc:ags:midcwp:162439&r=agr |
| By: | Alvaro Calzadilla; Ruth Delzeit; Gernot Klepper |
| Abstract: | Land use and land use change are determined as much by economic and institutional drivers as they depend on bio-physical conditions. Future pathways of socio-economic and environmental systems can only be assessed with scenarios which describe possible future paths of development. For this numeric models are one important tool. To capture the complex interactions between the development of regionally differentiated economic drivers, computable general equilibrium (CGE) models can be used. We discuss in a transparent way the inclusion of land and the representation of the complex agricultural production activities into DART-BIO, a CGE model. Implementing a scenario of changes in the preferences for meat and dairy products which is currently taking place in Asia, we find that these preference changes have only minor impacts on global agricultural prices while affecting regional production and trade. Results strongly depend on key parameter settings and highlight the importance of interlinkages between biofuel and livestock production |
| Keywords: | CGE Model, land use, biofuels, simulation model |
| JEL: | C61 Q16 Q42 |
| Date: | 2014–01 |
| URL: | http://d.repec.org/n?u=RePEc:kie:kieliw:1896&r=agr |
| By: | Brinda Viswanathan (Madras School of Economics); K. S. Kavi Kumar (Madras School of Economics) |
| Abstract: | This study explores the three way linkage between weather variability, agricultural performance and internal migration in India at state and district level using Indian Census data. We base all the analyses on a simultaneous equation model for panel data. The elasticity of inter-state out-migration rate with respect to the per capita net state domestic product is approximately (-)0.75. The crop-wise analysis, on the other hand, shows that the (negative) elasticities are higher and more substantial for rice (-1.85) than for wheat (-0.90). The district-level analysis shows larger magnitudes of estimated change in in-migration rates to relative changes in crop yields. The results suggest that the impact of yield change on the in-migration rate depends on both the inter-play between inter- and intra-district in-migration rates as well as the crop under consideration. The study findings could thus have significant policy relevance, especially in the context of global climate change and the prospect of migration serving as a potential adaptation strategy for people adversely affected by the impact of weather variability on crop yield. |
| Keywords: | Weather Variability; Agricultural Impacts; Internal Migration; Developing Countries; Climate Change; Adaptation |
| JEL: | O15 Q54 R11 |
| Date: | 2013–03 |
| URL: | http://d.repec.org/n?u=RePEc:mad:wpaper:2013-080&r=agr |
| By: | Israel, Danilo C.; Briones, Roehlano M. |
| Abstract: | This study examines "choke points" in the supply chain of two selected commodity groups that are of interest to the ASEAN region; within the HS15 group the study focuses on crude coconut oil (CNO); for HS03 the study covers fish and crustacean, mollusks, and other aquatic invertebrates (HS 03). For CNO, no major choke points have been identified from mill site to export stages; cost and delay factors can be found at the farm to mill stage, namely low farm productivity, poor postharvest practices (leading to low quality of copra), and inefficiencies in marketing to the mill. Meanwhile for fisheries, several choke points have been identified, namely: i) domestic road conditions (quality, vehicle capacity, quantity); ii) interisland shipping (high cost, inadequate service); iii) conditions in some ports (inadequate; a weak link in the cold chain); iv) compliance with SPS regulations; and v) certified laboratories (inadequate number). The study recommends specific types of road investments, competition policy in domestic shipping (both CNO and fisheries), industry restructuring in the case of coconut, and SPS measures in the case of fisheries. |
| Keywords: | infrastructure, Philippines, logistics, connectivity, agriculture supply chain, choke points |
| Date: | 2014 |
| URL: | http://d.repec.org/n?u=RePEc:phd:dpaper:dp_2014-07&r=agr |
| By: | Briones, Roehlano M.; Galang, Ivory Myka R. |
| Abstract: | This study examines the impact of a potential Philippines-European Union (EU) free trade agreement (FTA) on the agricultural sector. Static analysis indicates that potential gains to the agricultural sector of the Philippines are limited, primarily owing to the low size of initial agricultural trade with EU (compared to other trading partners), as well as moderate to low tariff and other trade barriers to EU products entering the country. CGE analysis confirms that the overall impact of bilateral tariff elimination leads to an overall increase in agricultural output, accompanied by a decline in price; hence, there is an increase in consumption of agricultural products. Impact on poverty is likewise positive, with improvements biased to the poorer households. By subsector, the largest output gains are projected for seaweeds and sugarcane, with 0.80 percent and 0.50 percent, respectively; increased access on EU markets are favorable for Filipino exporters of seaweeds, other fiber crops, tobacco leaf, forestry, ornamental plants, raw coffee, abaca, and cocoa. Meanwhile, the subsectors that are on the losing side (as shown by declining output) are cattle, raw rubber, chicken, and hogs. Fears about the negative repercussions of a Philippines-EU FTA on the poor turn out to be unfounded. Poverty incidence declines, and more so in rural than in urban areas. The greater decrease in poverty gap and squared poverty gap, compared with poverty incidence, implies that those who belong to households below the poverty threshold get the most benefits. It would seem that expectations of large benefits from a Philippines-EU FTA will not be found in agriculture, but elsewhere. Conversely, the agricultural sector does not face significant harm from a Philippines-EU FTA, even one involving sensitive products. Relaxation of trade barriers to EU even for sensitive products is warranted; not only would consumers gain (though minimally), but such a negotiation stance may serve as a powerful bargaining chip for gaining concessions on other areas. |
| Keywords: | computable general equilibrium (CGE), Philippines, agriculture, free trade area, impact assessment |
| Date: | 2014 |
| URL: | http://d.repec.org/n?u=RePEc:phd:dpaper:dp_2014-05&r=agr |
| By: | Reardon, Thomas |
| Abstract: | Myanmar faces a set of well-known challenges and problems, both in the overall economy and in rural areas in general and in agriculture. But Myanmar is also in one of the most blessed situations on the planet to expect rapid growth and poverty alleviation: it is next to (literally surrounded by) the fastest growing and largest food markets in the entire world, in China, India, Southeast Asia, and eventually Bangladesh, to name a few; the trade opportunities these represent are with only few historical parallels. Myanmar is in the best position to fuel rural development from regional trade, on the planet. |
| Keywords: | Agricultural and Food Policy, Community/Rural/Urban Development, International Relations/Trade, |
| Date: | 2014–01 |
| URL: | http://d.repec.org/n?u=RePEc:ags:midcpb:162437&r=agr |
| By: | Jean-Daniel Rinaudo (BRGM - Bureau de recherches géologiques et minières - Bureau de Recherches Géologiques et Minières (BRGM)); Auérlien Castel (BRGM - Bureau de recherches géologiques et minières - Bureau de Recherches Géologiques et Minières (BRGM)); Nicolas Faysse (UMR G-EAU - Gestion de l'Eau, Acteurs et Usages - Centre de coopération internationale en recherche agronomique pour le développement [CIRAD] : UMR90 - Institut de recherche pour le développement [IRD] - Irstea - AgroParisTech - Centre International des Hautes Études Agronomiques Méditerranéennes-Institut Agronomique Méditerranéen de Montpellier [CIHEAM-IAMM]) |
| Abstract: | This communication presents a framework to analyse the resilience of irrigated farms in Morrocco. It first presents a conceptual framework to analyse resilience at the farm level. The framework is then applied to a sample of farmers which were interviewed. We highlight very different perception of constraints to development and sources of risk. While some farmers identify and plan actions needed to enhance their resilience, others would only call for State intervention or even consider nothing can be done. We describe responses considered by farmers. We then investigate the factors determining buffer and adaptation capacity. A statistical classification is finally carried out to identify homogeneous farm groups in terms of resilience. |
| Keywords: | resilience; économie agricole; Maroc; eau souterraine |
| Date: | 2013–09–30 |
| URL: | http://d.repec.org/n?u=RePEc:hal:wpaper:hal-00931879&r=agr |
| By: | Krätschell, Karoline; Schmidt, Torsten |
| Abstract: | In this paper we use the frequency domain Granger causality test of Breitung/Candelon (2006) to analyse short and long-run causality between energy prices and prices of food commodities. We find that the oil price Granger causes all the considered food prices. However, when controlling for business cycle fluctuations this link exists especially at low frequencies. Thus, short-run phenomena like herd behaviour and speculation do not seem to have a considerable effect on the studied food prices. The relation between oil and food prices is rather established by long-term developments. A possible explanation for this could be the production of biofuel. -- |
| JEL: | C32 Q43 Q02 |
| Date: | 2013 |
| URL: | http://d.repec.org/n?u=RePEc:zbw:vfsc13:79798&r=agr |
| By: | Dambala Gelo, Steven F. Koch and Edwin Muchapondwa |
| Abstract: | Existing literature have rarely evaluated distributive effect of Joint Forest Management (JFM) augmented with improved market linkages for non-timber forest products nor have they accounted for heterogeneity in the welfare effects. We assess the distributional impact of a unique JFM in Ethiopia in which additional support for improved market linkages for non-timber forest products was provided. The analysis is based on matching and instrumental variable (IV) methods of quantile treatment effects (QTE) evaluation using household data from selected rural villages of Gimbo district, in southwest Ethiopia. The results confirm that the intervention affect outcomes heterogeneously across the welfare distribution. Specifically, the program was found to raise welfare for only those along upper half (median and above) of welfare distribution. Thus, we infer that the program is not pro-poor, and, therefore, is not equity enhancing. Our analysis also revealed that such distributional bias of the program benefit arises from elite capture. |
| Keywords: | Market Linkage, Joint Forest Management, Quantile Treatment Effects, Welfare Distribution |
| Date: | 2013 |
| URL: | http://d.repec.org/n?u=RePEc:rza:wpaper:400&r=agr |
| By: | Elisabeth Nindl (Department of Economics, Vienna University of Economics and Business) |
| Abstract: | This paper presents the first cross-country empirical evidence on the determinants of participation in Fairtrade and the impact of the export of Fairtrade certified products on agricultural growth in low and middle income countries. Using the number of certified producer organizations per country in 2006-2010 as a proxy for Fairtrade exports, estimation results indicate a small but significantly positive effect on the growth rate of per capita value added in agriculture that is largest in upper middle income countries. Given the particularly poverty-reducing effect of agricultural growth, we find empirical evidence that Fairtrade certification is indeed able to deliver its core values, but misses to target the very poor. |
| Keywords: | Fairtrade, agriculture, growth, poverty |
| JEL: | D3 O1 |
| Date: | 2014–01 |
| URL: | http://d.repec.org/n?u=RePEc:wiw:wiwwuw:wuwp160&r=agr |
| By: | de Walque, Damien; Dow, William H.; Gong, Erick |
| Abstract: | Transactional sex is believed to be an important risk-coping mechanism for women in Sub-Saharan Africa and a leading contributor to the HIV/AIDS epidemic. This paper uses data from a panel of women in rural Tanzania whose primary occupation is agriculture. The analysis finds that following a negative shock (such as food insecurity), unmarried women are about three times more likely to have been paid for sex. Regardless of marital status, after a shock women have more unprotected sex and are 36 percent more likely to have a sexually transmitted infection. These empirical findings support the claims that transactional sex is not confined to commercial sex workers and that frequently experienced shocks, such as food insecurity, may lead women to engage in transactional sex as a risk-coping behavior. |
| Keywords: | Population Policies,Health Monitoring&Evaluation,Gender and Health,Adolescent Health,Gender and Law |
| Date: | 2014–01–01 |
| URL: | http://d.repec.org/n?u=RePEc:wbk:wbrwps:6751&r=agr |
| By: | Manzano, George N. |
| Abstract: | In drawing up the negotiating stance of the Philippines in light of the Philippines-European Union (PH-EU) free trade agreement (FTA), it is important to articulate its offensive and defensive interests. Indications of the offensive and defensive interests can be gleaned from standard measures of competitiveness as well as complementarities of the partners. However, in operational terms, negotiators would require analysis that is carried out at more specific tariff levels. This paper proposes the framework to generate different offensive and defensive lists of commodities in the non-agricultural sector as input to the Philippine negotiators. Because the criteria that is used in generating the offensive and defensive lists is purely economic in nature, the negotiators are expected to weigh in the political and non-economic criteria to determine the final lists for negotiations in the PH-EU FTA. |
| Keywords: | Philippines, trade, free trade agreements (FTAs), trade policy, Philippine manufacturing, offensive interest |
| Date: | 2014 |
| URL: | http://d.repec.org/n?u=RePEc:phd:dpaper:dp_2014-04&r=agr |
| By: | Massimiliano Mazzanti; Susanna Mancinelli; Marianna Gilli |
| Abstract: | Innovation is a key element behind the achievement of desired environmental and economic performances. Regarding CO2, mitigation strategies would require cuts in emissions of around 80-90% with respect to 1990 by 2050 in the EU. We investigate whether complementarity, namely integration, between the adoption of environmental innovation measures and other technological and organizational innovations is a factor that has supported reduction in CO2 emissions per value added, that is environmental productivity. We merge new EU innovation and WIOD data to assess the innovation effects on sector CO2 performances at a wide EU level. We find that jointly adopting different innovations is not a widespread factor behind increases in environmental productivity. Nevertheless, even though complementarity is not a low hanging fruit, a case where ‘innovation complementarity’ arises is for manufacturing sectors, that integrate eco innovations with product innovations. One example of this integrated action is a strategy that pursue energy efficiency with product value enhancement. We believe that the lack of integrated innovation adoption behind environmental productivity performance is a signal of the current weaknesses economies face in tackling climate change and green economy challenges. Incremental rather than more radical strategies have predominated so far. The latter have been confined to industrial ‘niches’, in terms of number of involved firms. This is probably insufficient when we look at long-term economic and environmental goals. |
| Keywords: | Complementarity; Innovation; Climate Change; Sector Performance |
| JEL: | L6 O3 Q55 |
| Date: | 2014–01–28 |
| URL: | http://d.repec.org/n?u=RePEc:udf:wpaper:2014043&r=agr |
| By: | Sebastien Pouliot (Center for Agricultural and Rural Development (CARD)); Bruce A. Babcock (Center for Agricultural and Rural Development (CARD)) |
| Abstract: | The Environmental Protection Agency (EPA) proposed in November to reduce 2014 biofuel mandates. One concern expressed by EPA is that it will be difficult, if not impossible, to consume the 2014 target levels of ethanol in the Renewable Fuel Standard (RFS) because of infrastructure issues. Difficulty in meeting ethanol mandates is reflected into increased compliance costs and a measure of compliance cost is the price of the tradable ethanol credit known as a RIN (Renewable Identification Number). The price of RINs represents the gap between the cost of producing another gallon of ethanol and the price of ethanol that is needed to induce consumers to buy another gallon. Compliance with the ethanol mandates falls to owners of oil refineries who must purchase a specified number of RINs per gallon of gasoline produced. We show in previous work that increasing the number of stations that sell E85 decreases the ethanol price discounts needed to induce enough ethanol consumption to meet targets by making the fuel more accessible to consumers. Any reduction in required discounts directly leads to lower RIN prices and hence lower compliance costs. Thus, obligated parties faced with high RIN prices would have a strong incentive to invest in the infrastructure that would facilitate increases in ethanol consumption. As the cost of complying with RFS falls to owners of oil refineries, it is a natural position for them to oppose any further increase in mandated ethanol volumes. One argument that has often been made by the oil industry against increases in ethanol is that compliance costs will be passed on to consumers. This seems like a reasonable argument because this type of cost increase in any economic model will tend to lead to higher gasoline prices, hence higher consumer prices. Our objective in this study is to provide a transparent economic analysis of the impact on consumer fuel prices from increased ethanol mandates. One feature of our analysis is that it accounts for an increase in the consumption of E85, the most likely compliance path that would be taken in 2014 to meet increases in ethanol mandates. Each year, EPA establishes a percentage standard for ethanol by dividing the desired quantity of ethanol by the total anticipated domestic sales of unblended gasoline. Each producer of gasoline has an RVO (Renewable Volume Obligation) that is determined by multiplying the percentage standard by total domestic sales of gasoline. The RVO is met by acquiring RINs. If an obligated party’s sales of gasoline increases, so too does the RVO. This means that an obligated party can reduce the number of RINs that it needs to comply with the RFS by decreasing the volume of gasoline sales. This direct link between the cost of RINs and gasoline sales implies that increases in the cost of RINs reduces the quantity of gasoline that refiners will provide to consumers at any given gasoline price. Our model has separate demand curves for E10 and E85. The two demand curves are related because increases in E85 consumption come at the expense of E10. The model calculates the retail price of E85 that is needed to induce consumers to buy enough ethanol so that the number of RINs generated is adequate to meet oil refineries’ RVO obligations. The obligations are met through increased E85 consumption and reduced E10 consumption. Increased E85 consumption can only occur with a lower retail price of E85. Given E10 and E85 prices, we can calculate the value at wholesale for gasoline and ethanol. It is the difference between the value of ethanol at wholesale and the cost of producing the required quantity of ethanol that determines the RIN price. The compliance cost to oil refineries per gallon of gasoline is the product of the RIN price and the percentage standard. We find two direct effects of a binding ethanol mandate. The first is an increase in the wholesale price of gasoline because positive RIN prices increase the cost of producing gasoline. The second is a decrease in the ethanol price paid by blenders net of the RIN value. The net price of ethanol will decrease to induce consumers to consume enough ethanol to meet the mandate. Because most US consumers buy E10, the lower price of ethanol in the blend offsets at least some portion of the increased gasoline price. In addition to these two direct effects on the price of E10, there exists an indirect effect that works to lower E10 prices. To meet mandates beyond E10 requires an increase in E85 consumption, which results in a decrease in E10 consumption because some owners of flex vehicles switch fuels. The effect of substituting E85 for E10 is a net decrease in gasoline demand, which results in some reduction in wholesale gasoline prices. Whether the net effect of these three market forces results in a net increase or decrease in E10 pump prices requires the development of an economic model to sort out. We developed and calibrated such a model with the purpose of showing how feasible increases in ethanol blending mandates will affect the price of E10 under a range of possible conditions. We find that feasible increases in the ethanol mandate in 2014 will cause a small decline in the price of E10. That is, even though increased mandates increase gasoline prices, the offsetting effects from a decline in ethanol price and movement by motorists to E85 from E10 are enough to result in a net decrease in the price of E10. Our results should reassure those in Congress and the Administration who are worried that following the RFS commitment to expanding the use of renewable fuels will result in sharply higher fuel prices for consumers. There may be sound policy reasons that could justify Congress revisiting the RFS. However, concern about higher pump prices for consumers is not one of them. |
| Date: | 2014–01 |
| URL: | http://d.repec.org/n?u=RePEc:ias:cpaper:14-pb18&r=agr |
| By: | Niño Peña, Monica Patricia; Pelupessy, Wim |
| Abstract: | The purpose of this paper is to assess the effects that different competitiveness strategies based on commercial quality attributes may have on the livelihoods of small coffee growers in Colombia. Using a combination of global value chain and sustainable livelihood approaches, it appears that the impacts of traditionally applied material quality, symbolic and in-person services characteristics are quite different for the growers. The possibility of smallholders to benefit from quality attributes is greatly influenced by the global chain governance structure imposed by big multinational roasters in developed countries and the National Federation of Coffee Growers who acts as domestic lead firm and official external regulator in Colombia. The unequal power distribution in the chain has effects on growers’ income as they grasp direct benefits from the first transformations of coffee, but are far from the end product that consumers buy. Most of the value added during the coffee trans¬formation process accrues to the consuming country where branding, marketing and advertising are high-value generating activities. From the micro-level perspec¬tive it appears that endowments of key assets are not enough for growers to reach the poverty line through coffee production exclusively, while the socio-cultural assets of coffee growing are also threatened by disintegrating pressures from the nearby capital Bogotá. Further material and symbolic quality improvements may benefit the growers but are usually not enough to raise household income above the poverty line. A regional denomination of origin strategy may improve the local economic and cultural sustainability of coffee growing. |
| Keywords: | Colombia; coffee; livelihoods |
| Date: | 2014–01 |
| URL: | http://d.repec.org/n?u=RePEc:iob:dpaper:2014001&r=agr |
| By: | Andrew Mitchell |
| Abstract: | Resilience has gained significant prominence following the re-examination of the performance of the humanitarian and development aid systems in light of the two major food security crises in East and West Africa over the last two years, coupled with ongoing ‘post-2015’ negotiations on key global disaster risk reduction, climate change and development policy and resourcing. Resilience has largely been communicated by donor and other key actors as a political agenda, devoid of clear technical guidance as to its added value and how it changes programming on the ground. As a result, country staff are either cynical of its value, are confused as to what it means, or use it as another opportunity to attract funding or to justify their narrow institutional mandate. There are relatively few actors who engage with resilience armed with specific technical guidance informed by comprehensive risk and vulnerability analyses. The continued ‘improper’ application of resilience reinforces some views that this is another ‘buzzword’ or ‘fad’, devoid of real meaning for programming, and will mean that the approach will be eventually dropped from policy and programming when ‘the next big thing’ comes along. This study argues that resilience has sufficient technical added-value (distinct from resilience as a political agenda) and outlines how it can be applied to programming, and, in response to challenges on the ground how donors and key partners can incentivise integrating resilience into programming. There are also recommendations for further study to support further integration of resilience into programming. |
| Date: | 2013–12–16 |
| URL: | http://d.repec.org/n?u=RePEc:oec:dcdaaa:13-en&r=agr |
| By: | Ahlheim, Michael; Schneider, Friedrich |
| Abstract: | In many empirical Contingent Valuation studies one finds that household size, i. e. the number auf household members, is negatively correlated with stated household willingness to pay for the realization of environmental projects. This observation is rather puzzling because in larger households more people can benefit from an environmental improvement than in small households. Therefore, the overall benefit should be greater for larger households. A plausible explanation could be that household budgets are tighter for large families than for smaller families with the same overall family income. The fact that larger families can afford only smaller willingness to pay statements in Contingent Valuation surveys than smaller families with the same income and the same preferences might have consequences for the allocation of public funds whenever the realization of an environmental project is made dependent on the outcome of a Contingent Valuation study. In this paper we show how the use of household equivalence scales for the assessment of environmental projects with the Contingent Valuation Method can serve to reduce the discrimination of members of large families. -- |
| JEL: | D61 H43 Q51 |
| Date: | 2013 |
| URL: | http://d.repec.org/n?u=RePEc:zbw:vfsc13:79974&r=agr |
| By: | Moghaddasi, Reza; Eghbali, Alireza; Lakhaye Rizi, Parisa |
| Abstract: | Drought is the most important and destructive climate phenomenon which is usually of importance in a regional scale. Therefore, this study offers a fuzzy-based hybrid index in order to analyze the regional drought in Abadan and khoramshahr, Khuzestan, Iran. Influencing all aspects of human activity, drought does not have a comprehensive definition and an appropriate and general index to explore it. Consequently, in order to develop a model to evaluate and analyze drought, the fuzzy model has been used. The application of fuzzy logic to examine drought in Abadan-khoramshahr station demonstrated that fuzzy logic enables us to examine drought more accurately and appropriately because it takes into account the type of product (wheat or dates) in calculating the probability of drought. In furtherance of this aim, the fuzzy function related to the standardized Precipitation Index (SPI) and the standardized evapotranspiration index (SEI) have been combined and a new indicator called the standardized evapotranspiration and Precipitation index (SEPI) was developed. In the final fuzzy model, 81 rules have been utilized. In this study, the annual data of wheat and dates from 1994 to 2012 have been utilized (sometimes 2013 data have been used), and on this basis, the results of the model revealed that severe and continued droughts have occurred in 1999, 2007 and 2009 and the probability of drought for wheat and dates was 64.29 and 57.14 percent respectively in this period. |
| Keywords: | Water Requirement, Probability of Drought, wheat, dates, SEPI |
| JEL: | C15 O13 Q12 R11 |
| Date: | 2014–01–02 |
| URL: | http://d.repec.org/n?u=RePEc:pra:mprapa:53153&r=agr |
| By: | Bell, Peter N |
| Abstract: | In this paper I develop a theoretical model to analyze policy that restricts who can own land. I briefly review research related to such policy in Saskatchewan, Canada, and identify a standard supply-demand model that I extend in several ways. First, I replicate results for how policy affects prices and develop new results for how policy affects social welfare using comparative statics. Second, I extend the model to a dynamic setting where demand curves change over time and show that policy can affect price changes in variety of ways, which I refer to as comparative dynamics. Third, I conduct a series of simulations to compare my model and a standard model. I establish stylistic facts about data on price levels, differences, and ratios generated by the different models. |
| Keywords: | Farmland, ownership, policy, demand and supply, comparative statics, comparative dynamics, simulation |
| JEL: | C00 D00 Q15 |
| Date: | 2014–01–25 |
| URL: | http://d.repec.org/n?u=RePEc:pra:mprapa:53185&r=agr |
| By: | Jans, Jenny (Uppsala Center for Labor Studies); Johansson, Per (Uppsala Center for Labor Studies); Nilsson, J Peter (Uppsala Center for Labor Studies) |
| Abstract: | On normal days, the temperature decreases with altitude, allowing air pollutants to rise and disperse. During inversion episodes, a warmer air layer at higher altitude traps pollu- tants close to the ground. We show how readily available NASA satellite data on vertical temperature proles can be used to measure inversion episodes on a global scale with high spatial and temporal resolution. Then, we link inversion episode data to ground level pollution monitors and to daily in- and outpatient records for the universe of children in Sweden during a six-year period to provide instrumental variable estimates of the eects of air quality on children's health. The IV estimates show that the respiratory illness health care visit rate increases by 8 percent for each 10 m=m3 increase in PM10; an es- timate four times higher than conventional estimates. Importantly, by linking the health care data to detailed records of parental background characteristics, we show that chil- dren from low-income households suer signicantly more from air pollution than children from high income households. Finally, we provide evidence on the importance of several mechanisms that could contribute to the dierence in the impact of air pollution across children in rich and poor households. |
| Keywords: | Air pollution; Health; inversions; environmental policy; instrumental variable; nonparametric regression; socio-economic gradient in health |
| JEL: | I12 I14 J24 Q53 |
| Date: | 2014–01–20 |
| URL: | http://d.repec.org/n?u=RePEc:hhs:uulswp:2014_001&r=agr |