the political economy of agriculture for development today the small versus large scale debate revisited the role of agriculture in economic development and the development politics of promoting smallholder versus large scale agriculture have both been at the center of a long lasting and controversial debate using an innovative methodology which combines a value chain approach with input output analysis the growth multipliers and productivity of both farm types in guatemala are analyzed results show that smallholder agriculture has the same potential to stimulate output growth as large scale agriculture smallholder value chains include mainly informal sectors and create more jobs than commercial agriculture therefore a reorientation of agricultural and land policies toward small scale food producers and within a comprehensive policy of integrated rural development is not only necessary in terms of social equity but also for boosting economic development

bequests gifts and social security this paper analyses the very long run or stationary state impact of an unfunded social security system we use an overlapping generations model framework a key feature is that while parents care about their children and can leave non negative bequests to them children also care about their parents and can make non negative gifts to them we show that the possibility of negative net bequests may make social security less harmful to private wealth accumulation than would otherwise be the case a subsidiary finding is that risk loving behaviour may emerge for some households due to the nature of intergenerational transfers within family lines

optimal farm size in an uncertain land market the case of kyrgyz republic this article applies a real options model to the problem of land development making use of the 1998 2001 kyrgyz household budget survey we show that when the hypothesis of decreasing return to scale holds the relation between the threshold value of revenue per hectare and the amount of land cultivated is positive in addition the relation between the threshold and the amount of land owned is positive in the case of continuous supply of land and negative when there is discontinuous supply of land the direct consequence is that in the first case smaller farms will be more willing to rent land and exercise the option where in the second case larger farms will exercise first the results suggest three main conclusions i the combination of uncertainty and irreversibility is an important factor in land development decisions ii farmer behavior is consistent with the continuous profit maximization model and iii farming unit revenue tends to be positively related to farm size once uncertainty is properly accounted for

modeling the co movements between crude oil and refined petroleum markets abstract in this paper we investigate two types of asymmetries i e the asymmetry in the lower and upper tail dependences and the asymmetry in the propagation of crisis bubble between crude oil market and refined petroleum markets based on copula models thirteen copula models with different types of dependence structures and time varying dependence parameters are considered we find that in general the malm copula fits our sample data best based on aic criterion we find that lower and upper tail dependences are both positive indicating that crude oil and refined product markets tend to move together using the asymmetric copulas we find asymmetry in tail dependence between crude oil and heating oil returns and that between crude oil and jet fuel returns interestingly upper tail dependence is significantly greater than the lower tail dependence for the pre crisis period while the result is reversed for the post crisis period finally although our data prefers the nonexchangeable malm copula the asymmetry in the propagation of crisis bubble between crude oil and refined product returns is very weak

measuring contagion between energy market and stock market during financial crisis a copula approach abstract in this paper we apply time varying copulas to investigate whether a contagion effect existed between energy and stock markets during the recent financial crisis using the wti oil spot price the s p500 index the shanghai stock market composite index and the shenzhen stock market component index returns evidence was found for a significantly increasing dependence between crude oil and stock markets after the failure of lehman brothers thus supporting the existence of contagion in the sense of forbes and rigobon s 2002 definition moreover increased tail dependence and symmetry characterize all the paired markets this indicates that significant increases in tail dependence are an actual dimension of the contagion phenomenon and that crude oil and stock prices are linked to the same degree regardless of whether markets are booming or crashing during the sample period finally the contagion effect is found to be much weaker for china than the us the empirical results have potentially important implications for risk management

biodiesel as a motor fuel price stabilization mechanism abstract this article studies the capacity of biofuels to reduce motor fuel price fluctuations for this purpose we study dependence between crude oil and biodiesel blend prices in spain copula models are used for this purpose results suggest that the practice of blending biodiesel with diesel can protect consumers against extreme crude oil price increases

structural breaks dynamic correlations asymmetric volatility transmission and hedging strategies for petroleum prices and usd exchange rate abstract this paper investigates the influence of structural changes on the asymmetry of volatility spillovers asset allocation and portfolio diversification between the usd euro exchange market and each of six major spot petroleum markets including wti europe brent kerosene gasoline and propane using the bivariate dcc egarch model with and without structural change dummies the results provide evidence of significant asymmetric volatility spillovers between the u s dollar exchange rate and the petroleum markets moreover the model with the structural breaks reduces the degree of volatility persistence and leads to more appropriate hedging and asset allocation strategies for all pairs considered thus the findings have important implications for financial risk management

rockets and feathers the asymmetric speed of adjustment of uk retail gasoline prices to cost changes abstract the paper develops a quadratic quantity adjustment model to test the hypothesis put forward in the recent monopolies and mergers commission report that the speed of adjustment of uk retail gasoline prices to cost changes is more rapid when costs rise than when they fall and that the adjustment path is more concentrated around the mean value on the upswing using data from 1982 to 1989 evidence of faster and more concentrated responses to cost increases were found

is hedging the crack spread no longer all it s cracked up to be abstract the traditional approach to hedging the crude oil refining margin crack spread adopts a fixed 3 2 1 ratio between the futures positions of crude oil gasoline and heating oil however hedging the latter in arbitrary proportions might be more effective under some conditions the paper constructs optimal hedging strategies for both scenarios during the periods of relatively stable and volatile oil prices observed in recent years minimization of downside risk lpm 2 and variance are used as alternative hedging objectives the joint distribution of spot and futures price log returns is modeled using a kernel copula method the hedging performance of the constructed strategies is compared using hedging effectiveness expected profit and expected shortfall the results show that allowing for arbitrary proportions in the sizes of futures positions generally achieves a better hedging performance the advantage becomes particularly important during periods characterized by greater variation of the cross dependence between the price log returns of individual commodities in addition using lpm 2 as a hedging criterion can help hedgers to better track downside risk as well as lead to higher expected profit and lower expected shortfall

farm size land yields and the agricultural production function an analysis for fifteen developing countries abstract the paper analyzes the relationship between factor inputs land yields and labor productivity for farms of different size on the basis of fao farm management data for 15 developing countries for all but three countries a strong negative correlation is found between farm size on the one side and factor inputs and yields per hectare on the other the fitting of unconstrained production functions to the above data suggests that in only few cases the decline in yields for increasing farm size can be attributed to decreasing returns to scale the higher yields observed in small farms are mainly to be ascribed to higher factor inputs and to a more intensive use of land therefore where conspicuous labor surpluses exist the superiority of small farming provides solid arguments in favor of land redistribution such an agrarian reform would determine higher output higher labor absorption and a more equitable income distribution thus contributing in a decisive manner to the alleviation of rural poverty the paper also provides estimates of cross sectional production functions for the 15 countries analyzed empirical relations are found between the output elasticities of land labor and intermediate inputs and physical indicators of their scarcity the paper concludes by proposing a simple method for deriving a long term production function for agriculture

measurement of competitiveness in smallholder livestock systems and emerging policy advocacy an application to botswana farm level cross sectional data of 556 randomly selected livestock producers were used to investigate the competitiveness of smallholder beef farmers in botswana the results show the presence of inefficiency with about 74 of the variation in actual profit from maximum profit profit frontier between farms mainly arising from differences in farmers practices rather than random variability further the mean profit efficiency level of 0 58 suggests that there is a substantial scope to improve beef profitability in botswana significant profit efficiency drivers include among others education distance to market herd size access to information and access to income from crop production considering the importance of livestock sector for wealth creation and poverty eradication in the rural areas where poverty is more pronounced there is a need for appropriate development strategies and policies directed towards addressing these factors in particular there is need to invest in market infrastructure in order to improve market access hence profit efficiency of smallholder livestock farmers

evaluating the impact of mexico s land reform on agricultural productivity abstract in mexico land reform law and the terms of credit access suggest a priori that farmers in the land reform ejido sector should be less productive than private farmers analysis of studies comparing the productivity of individual ejido parcels and small private holdings however reveals no significant difference between the two sectors between tenure categories there is a de jure but not a de facto difference in small farmers control over resources partly because farmers circumvent restrictions implicit in the land reform the case for formal privatization of the ejido sector may be less compelling than has been suggested

the short and long run efficiency of energy precious metals and base metals markets evidence from the exponential smooth transition autoregressive models abstract the aim of this paper is to investigate the long and short run relationship between spot and futures prices of the energy precious metals and base metals markets we analyze daily data from january 1985 to february 2019 the empirical findings based on the cointegration test which follows a nonlinear process suggest that the spot prices of energy and metals assets have long run relationships with their futures prices nonparametric granger causality test results also indicate bi directional causality among futures and spot prices these findings indicate that the energy and metals markets are informationally efficient in the sense of fama 1970

agrarian structures urbanization and inequality summary this study examines the impact of agrarian structures on income inequality over the long run first it exhibits the relationship between land and income distribution by developing a theoretical model based on harris and todaro 1970 and lewis 1954 high land inequality increases income gini coefficients in the urban sector as well as the rural sector not only by creating congestion in the urban subsistence sector but also by feeding the growth of the urban reserve army of labor which pulls down the wages in the urban capitalist sector next the study investigates the empirical relationship between land inequality level of urbanization and income inequality using cross country datasets the estimation results support the theoretical model and indicate that the level of land inequality has a significant impact on determining the level of urbanization and urban and overall income inequalities moreover the analysis finds that overurbanization increases income inequality the empirical analysis controls for institutional factors like education inequality and the level of democracy the results present a stronger evidence on the land inequality s influence through urbanization than through education and democracy these results suggest that policymakers should have a broader view as to the importance of agrarian policies a progressive land reform or and subsidies protecting small peasantry can also reduce urban income inequality and poverty over the long run

the copula garch model of conditional dependencies an international stock market application abstract modeling the dependency between stock market returns is a difficult task when returns follow a complicated dynamics when returns are non normal it is often simply impossible to specify the multivariate distribution relating two or more return series in this context we propose a new methodology based on copula functions which consists in estimating first the univariate distributions and then the joining distribution in such a context the dependency parameter can easily be rendered conditional and time varying we apply this methodology to the daily returns of four major stock markets our results suggest that conditional dependency depends on past realizations for european market pairs only for these markets dependency is found to be more widely affected when returns move in the same direction than when they move in opposite directions modeling the dynamics of the dependency parameter also suggests that dependency is higher and more persistent between european stock markets

do gasoline prices respond asymmetrically to crude oil price changes the authors test and confirm that retail gasoline prices respond more quickly to increases than to decreases in crude oil prices among the possible sources of this asymmetry are production inventory adjustment lags and market power of some sellers by analyzing price transmission at different points in the distribution chain the authors attempt to shed light on these theories spot prices for generic gasoline show asymmetry in responding to crude oil price changes which may reflect inventory adjustment effects asymmetry also appears in the response of retail prices to wholesale price changes possibly indicating short run market power among retailers

do food and oil prices co move abstract this paper studies co movements between world oil prices and global prices for corn soybean and wheat using copulas several copula models with different conditional dependence structures and time varying dependence parameters were considered empirical results for weekly data from january 1998 to april 2011 showed weak oil food dependence and no extreme market dependence between oil and food prices these results support the neutrality of agricultural commodity markets to the effects of changes in oil prices and non contagion between the crude oil and agricultural markets however dependence increased significantly in the last three years of the sampling period even though upper tail dependence remained insignificant indicating that food price spikes are not caused by positive extreme oil price changes these results have implications for policy design risk management and hedging strategies

dependence structure between the equity market and the foreign exchange market a copula approach abstract this paper investigates the dependence structure between the equity market and the foreign exchange market by using copulas in particular several copulas with different dependence structure are compared and used to directly model the underlying dependence structure we find that there exists significant symmetric upper and lower tail dependence between the two financial markets and the dependence remains significant but weaker after the launch of the euro our findings have important implications for both global investment risk management and international asset pricing by taking into account joint tail risk

land reform as commenced business the evidence against stopping abstract in the new paradigm institutions are long term endogenous thus the aims of land reform must be compatible with replace or substitute for initial incentives and power structures many reforms e g compulsory collectives are not redefinition of land reform is therefore needed yet the case for private land redistribution with ceilings remains the inverse relationship rests firmly on lower cost labor transactions in small farms though large but competitive transport or processing firms which enjoy lower cost capital transactions may be needed crucial is the impact of the postreform structure on livelihoods especially for the growing rural majority near landless workers new style market based reforms have potential probably best combined with old style ceilings substantial compensation with urban taxpayers sharing costs alternative off farm prospects and progressive taxes on large landholdings or bequests

a threshold cointegration analysis of asymmetric price transmission from crude oil to gasoline prices abstract this study provides new supportive evidence for asymmetric adjustment in u s retail gasoline prices the asymmetric transmission is found to occur not just through the spot markets of crude oil and refinery gasoline but also through their future markets further evidence also shows that the observed asymmetry in price transmission primarily occurs downstream not upstream of the transmission process

the dependence and risk spillover between crude oil market and china stock market new evidence from a variational mode decomposition based copula method abstract this paper examines the dependence structure between crude oil market and china stock market over different investment horizons before and after the recent financial crisis by combining the variational mode decomposition vmd method with various static and time varying copulas based on the decomposed time series and the copula dependence the value at risk var conditional var covar and delta covar covar are quantified to analyze the upside and downside risk spillovers from oil market to china stock market in raw short and long run investment horizons before and after the financial crisis the empirical results show that first the recent financial crisis enhances the dependences between the crude oil market and china stock market and the long run dependence increases more significantly than that of short run for the raw return series there are symmetric upper and lower tail dependencies in full sample and pre crisis subsample periods but an average dependence in post crisis subsample period second the var of china stock market increases heavily around the financial crisis but the average var after the crisis deceases compared to the risk before the crisis third the risk spillovers from crude oil price to china stock market are found in each sample periods before the crisis however it mainly exists in long run horizon while after the crisis it happens in both short and long run horizons finally the risk spillovers from oil price to china stock market display strong asymmetric features with larger long term downside risk spillovers in post crisis subsample

the economic value of co movement between oil price and exchange rate using copula based garch models article i nfo the us dollar is used as the primary currency of international crude oil trading as such the recent substantial depreciation in the us dollar has resulted in a corresponding increase in crude oil prices in addition oil price and exchange rate returns have been shown to be skewed and leptokurtic and to exhibit an asymmetric or tail dependence structure therefore this study proposes dynamic copula based garch models to explore the dependence structure between the oil price and the us dollar exchange rate more importantly an asset allocation strategy is implemented to evaluate economic value and confirm the efficiency of the copula based garch models in terms of out of sample forecasting performance a dynamic strategy based on the cgarch model with the student t copula exhibits greater economic benefits than static and other dynamic strategies in addition the positive feedback trading activities are statistically significant within the oil market but this information does not enhance the economic benefits from the perspective of an asset allocation decision finally a more risk averse investor generates a higher fee for switching from a static strategy to a dynamic strategy based on copula based garch models

the future of small farms trajectories and policy priorities summary while smallholder development has in the past led to reductions in poverty and hunger does this still apply in today s more globalized world this paper reviews the debates on the contemporary role of agriculture in development and the case for small farms in light of the rise of supermarkets lower commodity prices and liberalized trade agricultural research funding environmental change hiv aids and changing policy ideas although the answers vary greatly by context for many low income countries smallholder development remains a key option the policy agenda however has changed in addition to providing public goods the growing challenge is to overcome market failures which is largely a matter of institutional innovation

biofuel related price transmission using renewable identification number prices to signal mandate regime this paper improves on existing methods of testing price links between biofuels petroleum petroleum products and agricultural commodity feedstocks by incorporating information contained in the prices of renewable identification numbers rins that are used for biofuel mandate compliance theoretical equations are developed to show the role rin prices can play in the relationships among energy biofuel and agricultural commodity prices rin price data are used a to infer values of fuels where market data are unavailable and b to define binding and non binding mandate regimes a specific empirical exercise exploits the rin price data to conduct cointegration tests on high frequency data representing spot and futures prices relating to ethanol and biodiesel from february 2009 through march 2015 finding little evidence of short term biofuel and petroleum product substitution during this period

evaluating density forecasts with applications to financial risk management density forecasting is increasingly more important and commonplace for example in financial risk management yet little attention has been given to the evaluation of density forecasts the authors develop a simple and operational framework for density forecast evaluation they illustrate the framework with a detailed application to density forecasting of asset returns in environments with time varying volatility finally the authors discuss several extensions copyright 1998 by economics department of the university of pennsylvania and the osaka university institute of social and economic research association

on price risk and the inverse farm size productivity relationship abstract the oft observed inverse relationship between farm size and productivity has elicited several explanations having important policy and theoretical implications using advances in the analysis of price risk effects on producer behavior and a simple two period model of an agricultural household that both produces and consumes under price uncertainty at the time labor allocation decisions are made this paper demonstrates analytically that a non degenerate land distribution and price risk can together produce an inverse relationship even absent any of the more common explanations empirical evidence from madagascar confirms the plausibility of this intuitive explanation for the phenomenon

price relationships in the petroleum market an analysis of crude oil and refined product prices in this paper the relationships between crude oil and refined product prices are investigated in a multivariate framework this allows us to test several partly competing assumptions of earlier studies in particular we find that the crude oil price is weakly exogenous and that the spread is constant in some but not all relationships moreover the multivariate analysis shows that the link between crude oil prices and several refined product prices implies market integration for these refined products this is an example of supply driven market integration and producers will change the output mix in response to price changes

new evidence on asymmetric gasoline price responses in a 1997 paper borenstein cameron and gilbert bcg claim that gasoline prices rise quickly following an increase in the price of crude oil but fall slowly following a decrease this note estimates an error correction model with daily spot gasoline and crude oil price data over the period 1985 1998 and finds no evidence of asymmetry in wholesale gasoline prices the sources of the difference in results are twofold first we use the standard engle granger two step estimation procedure whereas bcg used a nonstandard estimation methodology second even using bcg s nonstandard specification the use of daily rather than weekly data yields little evidence of price asymmetry

economic efficiency in polish peasant farming an international perspective one decade following the market transition in poland the agricultural sector still exhibits low productivity policy makers often describe the sector as fragmented and inefficient to understand why small scale farming in poland is inefficient despite longstanding secure property rights a survey of economic efficiency in southern agriculture was conducted and compared with limited studies of efficiency in poland the most important issues particularly related to farm size and efficiency are price risk uncertainty and low rural development comparative studies across regions with varying institutional arrangements and economic organization are powerful but must be made carefully and critically

how do crude oil prices co move a copula approach abstract this paper examines the dependence structure between crude oil benchmark prices using copulas by considering several copula models with different conditional dependence structures and time varying dependence parameters we find evidence of significant symmetric upper and lower tail dependence between crude oil prices these findings suggest that crude oil prices are linked with the same intensity during bull and bear markets thus supporting the hypothesis that the oil market is one great pool in contrast with the hypothesis that states that the oil market is regionalized our findings on crude oil price co movements also have implications for risk management hedging strategies and asset pricing

dynamic stochastic copula models estimation inference and applications we propose a new dynamic copula model where the parameter characterizing dependence follows an autoregressive process as this model class includes the gaussian copula with stochastic correlation process it can be viewed as a generalization of multivariate stochastic volatility models despite the complexity of the model the decoupling of marginals and dependence parameters facilitates estimation we propose estimation in two steps where rst the parameters of the marginal distributions are estimated and then those of the copula parameters of the latent processes volatilities and dependence are estimated using efficient importance sampling eis we discuss goodness of t tests and ways to forecast the dependence parameter for two bivariate stock index series we show that the proposed model outperforms standard competing models

commodity futures and market efficiency we propose a comprehensive treatment of the leverage effect i e the relationship between returns and volatility of a specific asset focusing on energy commodities futures namely brent and wti crude oils natural gas and heating oil after estimating the volatility process without assuming any specific form of its behavior we find the volatility to be long term dependent with the hurst exponent on a verge of stationarity and non stationarity to overcome such complication we utilize the detrended cross correlation and the detrending moving average cross correlation coefficients and we find the standard leverage effect for both crude oils and heating oil for natural gas we find the inverse leverage effect additionally we report that the strength of the leverage effects is scale dependent finally we also show that none of the effects between returns and volatility is detected as the long term cross correlated one these findings can be further utilized to enhance forecasting models and mainly in the risk management and portfolio diversification

rural market imperfections and the farm size productivity relationship evidence from pakistan the subject of this article is the relationships between farm size and productivity and between farm size and profitability in the developing countries the recent controversies over the inverse size output relationship are reviewed and a framework is provided that explains the inverse relationship based on plausible assumptions about imperfections in the markets for labor land credit and risk from this framework a set of testable hypotheses are derived the hypotheses are tested on recent farm level panel data from pakistan a strong inverse relationship between farm size and yield is present in the sample even when household fixed effects are used to account for unobserved heterogeneity moreover the suggested market imperfections framework is consistent with the data

are oil and gas stocks from the australian market riskier than coal and uranium stocks dependence risk analysis and portfolio optimization abstract this article models the dependence risk and resource allocation characteristics of two 20 stock coal uranium and oil gas sector portfolios from the australian market in the context of the global financial crisis of 2008 2009 the modeling framework implemented consists of pair vine copulas and linear and nonlinear portfolio optimization methods with respect to five risk measures the paper s objectives are to find out if the oil and gas stocks are riskier than the coal and uranium stocks to identify the optimization method and risk measure that produce the best risk return trade off to recognize the stocks in which the optimal weight allocations converge on average and to acknowledge the vine copula model that best accounts for the overall dependence of the energy portfolios the research findings indicate that the oil stocks have higher dependence risk than the coal uranium and gas stocks in financial crisis periods the higher risk of the oil stocks is confirmed by the larger concentration of symmetric and asymmetric dependence they have in the negative tail the canonical vine c vine copula model is observed to better capture the overall dependence of the energy portfolios the combination of a pair c vine copula and nonlinear portfolio optimization produces the highest return relative to risk the optimal weight allocations converge on average in some stocks

is small beautiful farm size productivity and poverty in asian agriculture the debate on the relationship between farm size and productivity has gone through a complete circle in the 1960s it was perceived that small farms were efficient because they can fully use their resources particularly family labor and they can monitor their production activities closely but in the 1970s and 1980s as many asian countries rapidly moved towards industrialization and urbanization small farms were considered a major obstacle in this process