governance and agricultural productivity a cross national analysis abstract in this study we examine the relationship between governance and agricultural performance by employing the world bank s aggregate governance indicators based on a cross country panel sample two methods are employed to test the hypothesis that better governance fosters agricultural productivity the empirical results of both methods support the hypothesis as for the first method the estimation results of the widely used inter country aggregate agricultural production function show that a country with better governance can produce more agricultural outputs given the same amounts of agricultural inputs the same education level and the same climate condition as for the second method the empirical results of a structural equation model reveal that given the same amounts of agricultural capital stock and land an agricultural worker in a country with better governance produces more better governance can indirectly improve agricultural productivity by driving agricultural capital accumulation our empirical work lends support to the claim of hayami and ruttan hayami y ruttan v 1985 agricultural development an international perspective john hopkins university press baltimore that governance is a basic factor explaining the poor economic performance of many developing countries in order to improve the agricultural performance of many developing countries apart from physical and education investments more emphasis should be placed on improving the governance infrastructure of these countries

unit root tests and the statistical pitfalls of seasonal adjustment the case of u s postwar real gross national product unit root tests applied to the postwar seasonally adjusted quarterly gross national product series strongly support the null hypothesis of the presence of a unit root in the data generating process evidence reported here with seasonally unadjusted data is far less conclusive it is explained why seasonal adjustment procedures may alter the outcome of conventional tests

the role of empowerment in agricultural production evidence from rural households in niger we use new household and individual level weai data from the tahoua region of niger and estimate a variable coefficient cobb douglas production function in which traditional inputs interact with tw

examining crop price effects on production decision and resource allocation an ex ante approach this article examines the output price effects on the us crop production employing an ex ante approach to the differential systems of input demand and output supply the estimation results of the

implications of agricultural trade liberalization for the developing countries abstract the developing countries as a group could expect to experience only small welfare gains if they chose not to actively participate in agricultural trade liberalization and relied solely on the benefits of partial liberalization in the oecd countries participation along the lines of the dunkel package with the developing countries reducing positive assistance by less than the developed countries would yield gains of the order of us 20 billion more comprehensive participation in trade liberalization involving reductions of both positive and negative protection would almost triple these welfare gains while some developing countries do not gain from trade liberalization even with full participation the number of such countries and the magnitude of their losses are greatly reduced

agricultural distortions structural change and economic growth a cross country analysis taxing agriculture to mobilize resources for industrialization has been a widely used development strategy using novel cross country time series data sets with direct measures of agricultural taxation we examine how a policy bias against agriculture affects the speed of convergence in income per capita structural change and economic growth we find that distortionary agricultural policies in poor economies can account for the emergence of convergence clubs in our sample by significantly retarding their structural transformation and economic growth overall we find no evidence suggesting that policies that discriminate against agriculture have been beneficial for long term economic growth

the econometrics of damage control why specification matters the contribution of damage control agents to production differs fundamentally from that of standard inputs lands labor capital this paper develops an econometric model based on the key characteristics of damage control agents and examines its properties it demonstrates that standard production function specifications overestimate damage control agent productivity and have erroneous implications for the evolution of damage control agent productivity and use in response to changing environments e g the spread of pest resistance it also proposes several alternative specifications and discusses methods for estimating them

changes in the behavior of output in the united kingdom 1856 1990 abstract this paper reports evidence of major increases in the persistence of output as well as contributions of low frequency components to the variance of output growth for the united kingdom during 1856 1990 these results are contrary to those obtained by jaeger 1990

does real u k gdp have a unit root evidence from a multi century perspective we employ linear and nonlinear unit root tests to examine the stationarity of five multi century historical u k series of real output compiled by the bank of england three series span 1270 to 201

prices and productivity in agriculture developing countries often tax agriculture heavily a practice that might affect the productivity as well as the quantity of resources allocated to agriculture a variable coefficient cross country agricultural production function is estimated with past price expectations among the determinants of the production coefficients productivity s responsiveness to those expectations implies that had these developing economies eliminated price interventions agricultural productivity would have increased on average by about a fourth copyright 1993 by mit press

unpacking the meaning of market access evidence from rural kenya summary this paper critically examines the dimensions of market access using farm panel survey data from kenya we investigate changes in ten indicators of market access during the 1997 2010 post liberalization period we find major improvements in certain market access conditions and little change in others there is generally low correlation between alternative indicators of market access all purpose indicators may not accurately reflect specific market access conditions of interest distances to physical infrastructure are often not representative of farmers access to markets changes in specific market access conditions may have more to do with the behaviors of marketing agents we consider the implications of these findings for agricultural marketing policies and for research methods

quality adjusted price and quantity indices for pesticides quality adjusted price indices are calculated for pesticides used on major crops in u s agriculture for 1967 92 using hedonic methods pesticide potency hazardous characteristics and persistence in the environment are used as quality characteristics separate hedonic functions are estimated for pesticides by end use crop and major pesticide class price indices are aggregated using chained tornqvist indices adjusted quantity indices are computed using pesticide expenditures the adjusted price index rose steadily reaching in 1992 around 2 5 times the level of 1968 pesticide use at constant quality peaked in 1981 at a level substantially higher than the peak reached by the unadjusted index

unit root and trend breaks in per capita output evidence from sub saharan african countries abstractthis article examines the nonstationary properties of per capita real output in 28 sub saharan african ssa countries covering the period 1960 2014 the sequential testing approach proposed by kejriwal and lopez 2013 econometric reviews 32 8 892 927 is used to categorize ssa countries into growth shift level shift and linear trend hypotheses based on the presence or not of breaks in slope and or level of the trend function the break dates are associated to major historical or economic events such as sociopolitical crisis commodity price fluctuations on international market the discovery and the exploitation of mineral deposits or unfavourable environmental and climatic conditions the empirical evidences of appropriate unit root tests fail to reject the unit root hypothesis in all the countries suggesting that a shock would have a permanent effect on growth process and stabilization policies may be implemented in dealing with income fluctuations

ldc agriculture nonparametric malmquist productivity indexes abstract this paper examines changes in agricultural productivity in 18 developing countries over the period 1961 1985 we use the nonparametric output based malmquist index to examine whether the results from such an approach confirm results from other methods that have indicated declining agricultural productivity in less developed countries ldcs the results confirm previous findings indicating that at least half of these countries have experienced productivity declines in agriculture we also found that those countries that tax agriculture most heavily had the most negative rates of productivity change

long memory and persistence in aggregate output abstract we examine persistence in u s aggregate output by estimating fractionally integrated arima models these models provide better low frequency approximations to the wold representation than previous stochastic specifications and earlier results on the importance of a permanent component emerge as special cases we find evidence of long memory which induces persistence though this long memory need not be associated with a unit root our point estimates indicate that macroeconomic shocks while persistent are distinctly less persistent than many earlier studies suggest however confidence intervals associated with the long run response are quite wide

the nonstationarity of aggregate output some additional international evidence in this paper the stationarity of aggregate output is examined using the scaled variogram for a sample of twelve countries it is argued that if the true data generating process of output is stationary around a deterministic trend with a change in mean and or growth rate the results of previous studies are biased once the authors allow for a one time exogenous shock the conclusions are indeed less clear cut and for some countries even reversed copyright 1994 by ohio state university press

debt deficits and inflation an application to the public finances of india abstract the paper studies the solvency of the indian public sector and the eventual monetization and inflation that would be implied by stabilization of the debt gnp ratio in the absence of changes in the primary deficit the nonstationarity of the discounted public debt suggests that indefinite continuation of the pattern of behavior reflected in the historical time series process is inconsistent with the maintenance of solvency this message is reinforced by the recent behavior of the debt gnp ratio and of the ratio to gnp of the sum of the primary budget surplus and seigniorage our estimates of the base money demand function suggests that even maximal use of the inflation tax would not be sufficient to restore solvency measures to reduce the primary deficit are therefore unavoidable

nonlinearities in real exchange rate determination do african exchange rates follow a random walk in this article we aim at modelling the long run behaviour of the real effective exchange rates reer for a pool of african countries not much attention has been paid to this group of countries in particular to the existence of nonlinearities in the long run path of such a variable controlling for two sources of nonlinearities i e asymmetric adjustment to equilibrium and nonlinear deterministic trends allows us to gain some insight about the behaviour of the african reer we find that these sources of nonlinearities help us to explain the apparent unit root behaviour found applying linear unit root tests for most of the countries

effective costs and chemical use in united states agricultural production using the environment as a free input a cost function based production model is used to represent patterns of input use and output production in u s agriculture and the implied costs of induced reductions in risk from agricultural chemicals bad outputs we estimate and evaluate shadow values for these harmful outputs and the implied input and output specific substitution patterns with a focus on the impacts on pesticide demand and its quality and quantity components using state level data we find these measures to be statistically significant vary substantively by region and imply increased demand for effective pesticides associated with improvements in quality from embodied technology copyright 2002 oxford university press

output and unemployment dynamics in the united states 1950 1985 for us data over 1950 1985 the stochastic components of gnp growth and the unemployment rate appear to be stationary and there is substantial feedback between these variables the unconditional mean rate of unemployment in a joint model thus provides a natural benchmark in discussions of the business cycle a bivariate var model is used to describe output unemployment dynamics to estimate the degree of persistence of output innovations and to decompose output into trend and cycle the bivariate results are interpreted using a restricted var and it is shown that a closely related cyclical measure can be obtained directly from the okun s law equation

a measure of the u s output gap abstract an autoregressive distributed lag regression of the unemployment rate on output growth is structurally stable over the 1890 1986 period inverting this equation yields a measure of the output gap which is not subject to the spurious detrending problem

simple econometrics of pesticide productivity this paper develops a multioutput generalization of the lichtenberg zilberman damage control technology the dual representation of the technology is shown to be conditionally additive in the price of abatement activities and other prices an econometric procedure for estimating the dual technology is developed and applied to an aggregate u s agricultural data set the conditionally additive nature of the model allows estimation of pest damage from the dual technology our estimates of aggregate u s pest damage are much lower than previous estimates

trends and cycles in macroeconomic time series two structural time series models for annual observations are constructed in terms of trend cycle and irregular components the models are then estimated via the kalman filter using data on five u s macroeconomic time series the results provide some interesting insights into the dynamic structure of the series particularly with respect to cyclical behavior at the same time they illustrate the development of a model selection strategy for structural time series models

the unit root hypothesis for aggregate output may not hold after all new evidence from a panel stationarity test with multiple breaks author affiliation diego romero avila pablo de olavide university department of economics carretera de utrera km 1 41013 seville spain dromtor upo es acknowledgment the author would like to thank seminar participants at pablo de olavide university and dg economics of the european central bank and two anonymous referees for useful comments and suggestions 1 introductionsince the seminal work by nelson and plosser 1982 researchers have paid considerable attention to the presence of stochastic trends in macroeconomic variables that work also changed the way macroeconomists think about secular trends and short run fluctuations in business cycles since the existence of a unit root in output purports that shocks are permanent short run fluctuations cannot be explained by the traditional view as deviations around a deterministic trend that represents the secular component of the series instead the trend function itself can fluctuate as a result of permanent shocks king et al 1991 found that supply factors are important in explaining economic fluctuations but may not be the lone source of short run fluctuations campbell and mankiw 1987 stressed that demand shocks may also be the source of permanent shocks to output the existence of a high degree of persistence in output has important implications in macroeconomics for example the keynesian view that most shocks to output are transitory and output fluctuations are temporary deviations from the secular trend is inconsistent with a unit root in output on the contrary the real business cycle view conceives fluctuations as largely the result of real permanent shocks essentially of a technological nature this has important implications for economic policy since stabilization policies lose their effectiveness when variations of output are mainly permanent thus running counter to the keynesian view much of the empirical literature has focused on the nonstationarity properties of real u s gross national product gnp to cite a few studies perron and phillips 1987 schwert 1987 campbell and mankiw 1987 and perron 1988 fail to reject the null hypothesis of a unit root in real u s gnp these results have not gone unchallenged christiano and eichenbaum 1990 and rudebusch 1993 highlighted the low power of standard unit root tests of the augmented dickey and fuller 1979 type to distinguish between the trend stationary and unit root behavior in aggregate output the development of cross country data sets such as the long gross domestic product gdp series provided by maddison 1989 and the penn world table pwt constructed by summers and heston 1990 has allowed researchers to provide international evidence on the unit root behavior in aggregate output for instance wasserfallen 1986 found a unit root in gnp series for some organization for economic co operation and development oecd countries over the postwar era kormendi and meguire 1990 confirmed the existence of a unit root in output for twelve oecd countries over the period 1870 1985 1 however the seminal work of perron 1989 uncovered the fact that nonstationarity may conceal the existence of stationarity with structural change showing that standard unit root tests tend to misinterpret trend stationarity with a structural break as a unit root by exogenously imposing a structural break in real u s gnp perron 1989 was able to strongly reject the unit root hypothesis however zivot and andrews 1992 provided slightly less evidence of a unit root in real u s gnp using a test that allowed for a structural break that was endogenously determined from the data in an international context zelhorst and de haan 1994 1995 found evidence for oecd countries that over long time periods where the presence of structural change becomes more likely the null of a unit root in output tends to be rejected in favor of regime wise stationarity

is agricultural productivity in developing countries really shrinking new evidence using a modified nonparametric approach abstract nonparametric productivity analyses performed to date show that most developing countries are experiencing relatively rapid technical regress in agriculture we discuss the plausibility of these results and argue that they stem from the existence of biased technical change and the definition of technology used we reestimate the malmquist index for a group of developing countries using a different definition of technology and find that most developing countries in our sample are experiencing positive productivity growth with technical change being the main source of this growth

are there increasing returns to pollution abatement empirical analytics of the environmental kuznets curve in pesticides abstract according to the environmental kuznets curve ekc hypothesis economic growth and the reduction of environmental degradation are compatible goals an inverted u shaped relationship between economic performance and environmental pollution suggests that empirically an economy is associated with smaller levels of pollution after some threshold income point one potential explanation for the empirical evidence of an ekc is increasing returns to pollution abatement where the abatement efficiency rises with an increase in the scale of abatement doubling the clean up efforts more than doubles the abatement of pollution as this efficiency gain makes abatement less expensive pollution might fall as more abatement is undertaken this study tests the hypothesis that there are increasing returns to abating pollution empirical evidence on environmental risks in the us agricultural sector since 1970 support the existence of increasing returns in addition i estimate the productivity of pollution abatement using refined empirical productivity measurement methods and explicitly control the level of technology the results show the importance of including an environmental productivity variable in the ekc framework

international productivity patterns accounting for input quality infrastructure and research in this paper we present measures of land and labor productivity for a group of ninety eight developed and developing countries using an entirely new data set with annual observations spanning the past three decades the substantial cross country and intertemporal variation in productivity in our sample is linked to both natural and economic factors we extend previous work by dealing with multiple sources of systematic measurement error in conventional agricultural inputs the mix of conventional inputs indicators of quality of agricultural inputs and the amount of publicly provided infrastructure are all significant in explaining observed cross sectional differences in productivity patterns

trust in lending social capital and joint liability seed loans in southern zambia summary this paper identifies factors associated with high repayment performance by collectively liable groups of seed borrowers in southern zambia the results suggest that some factors facilitating collective action within seed groups such as their size are associated with a higher repayment performance in addition community based cognitive social capital proxied here by generalized trust is shown to be strongly associated with repayment performance this suggests that attitudes and values shared by community members create an environment in which seed borrowers honor their engagements although church participation and fear of witchcraft can weaken mutual monitoring of loan use and peer pressure for repayment

mergers stock prices and industrial production further evidence abstract economic theory has been developed to correlate mergers and stock prices and mergers and industrial production this study tests for significant relations among annual mergers stock prices and industrial production and examines whether multiple time series models can forecast annual mergers more accurately than a univariate merger model we do not find that the mean square forecasting error of the multivariate time series model is significantly less than the mean square forecasting error of the univariate merger model the stock price series does not aid in forecasting mergers

model evaluation based on residual analysis of two similar models models that may appear to have different properties may in fact produce residuals that differ only in subtle ways by analysing the relationships between model residuals the problems in distinguishing between models can perhaps be discovered as illustrated by the econometric examples considered regressing residuals gives the long memory residual which is the difference between two models but this difference is very subtle and deeply hidden which explains why the traditional standard technique does not find this difference

an investigation into adequate data for estimating annual earnings time series models abstract the purpose of this study is to examine the stability of corporate earnings per share eps time series models as the length of the time series are altered evidence is found to support the stationarity of corporate eps data furthermore outlier analysis is employed and supports the long run stability of corporate earnings series

total factor productivity growth in agriculture a malmquist index analysis of 93 countries 1980 2000 in this paper we examine levels and trends in agricultural output and productivity in 93 developed and developing countries that account for a major portion of the world population and agricultural output we make use of data drawn from the food and agriculture organization of the united nations and our study covers the period 1980 2000 due to the non availability of reliable input price data the study uses data envelopment analysis dea to derive malmquist productivity indexes the study examines trends in agricultural productivity over the period issues of catch up and convergence or in some cases possible divergence in productivity in agriculture are examined within a global framework the paper also derives the shadow prices and value shares that are implicit in the dea based malmquist productivity indices and examines the plausibility of their levels and trends over the study period

market and cost structure in the u s beef packing industry a plant level analysis a resurgence of consolidation in the u s meat packing industry in the past few decades has stimulated academic and policy debate issues raised include the role of cost economies in driving these patterns and the effects on the agricultural sector cattle producers from market power here plant level cost and revenue data for u s beef packing plants are used to estimate a cost based model incorporating cattle and output market pricing behavior the robust results indicate little market power exploitation in either the cattle input or beef output markets and that any apparent evidence is counteracted by cost efficiencies such as utilization and scope economies copyright 2001 oxford university press

the econometrics of damage control lichtenberg and zilberman argue correctly that when biological and physical processes are considered we are able to delineate two components of actual realized crop yields potential output the maximum quantity of product obtainable from any given combination of inputs and losses caused by damaging agents present in the environment p 262 they further argue that damage control agents should be defined in terms of their contribution to the abatement effort and hence should enter the production function as an argument of the damage abatement function to demonstrate the consequences of their claims lichtenberg and zilberman make an ad hoc choice of a cobb douglas functional form for crop yield exogenous factors such as pest prevalence and weather conditions are ignored although they note that omission of these environmental factors will result in misspecification of the production relationship p 267

capital services in u s agriculture concepts comparisons and the treatment of interest rates this paper begins with a review of the methods and assumptions used to measure capital service flows two data series on capital inputs in u s agriculture are briefly described and compared we show that measures of capital services are sensitive to the treatment of interest rates notably the use of fixed versus variable market rates significantly affects measures of the quantity and productivity of agricultural capital in the united states we conclude that when calculating capital usage in u s agriculture the use of a fixed interest rate generates more plausible estimates than the use of an annual market rate

a conceptual framework for community based health insurance in low income countries social capital and economic development summary the international policy model linking community based health insurance cbhi and universal coverage for health care in low income countries is implicitly determined by the development of mutual health insurance in 19th century europe and japan the economic and health system frameworks employed in cbhi policy have not sufficiently taken into account contextual considerations social capital theories could contribute to understanding why generally cbhi does not achieve significant and sustainable levels of population coverage a framework of social capital and economic development is used to organize and interpret existing evidence on cbhi this suggests that solidarity trust extra community networks vertical civil society links and state society relations affect the success of cbhi aligning schemes to social determinants of cbhi could result in structures that differ from those proposed by current analytic frameworks

tracing the effects of agricultural commodity prices and food costs we estimate a system of product and input demand equations for food processing industries to trace the links among farm commodity prices food processing costs and food prices disembodied technical change which likely reflects increasing consumer demand for convenience and product variety has sharply reduced agricultural materials demand relative to most other food processing inputs this implies weakening impacts of farm price shocks on food prices but improving quality and falling relative prices for agricultural inputs in combination with increasing factor substitution has counteracted these forces to encourage greater usage of agricultural inputs in food processing and limit these trends food prices today often appear less responsive to farm price shocks than in the past a development sometimes attributed to failures in market institutions however powerful long run technological and social changes leading to adaptations in production processes and food consumption patterns have also altered the demand for primary agricultural materials by changing the structure of food processing industries the social shifts surrounding the expanded role of women in the labor force represent one striking example of such changes the fraction of married women in the labor force less than one third in 1960 rose sharply through the next three decades before stabilizing at around 61 in the 1990s such demographic shifts increased the demand for food products requiring less home preparation time which in combination with enhanced technology has led to more in plant processing of agricultural materials and likely a growing share of nonagricultural inputs in

the intercountry agricultural production function and productivity differences among countries abstract the sources of differences in labor productivity in agriculture between developed countries dc s and less developed countries ldc s are identified by estimating an aggregate agricultural production function based on cross county data for 1960 1970 and 1980 the production function was found to be stable over the entire period agriculture in the dc s was characterized by increasing returns and in the ldc s by constant returns to scale the results imply that unfavorable man land ratios do not represent an immediate barrier to rapid agricultural development in the low income ldc s but they may create a serious agricultural adjustment problem as those countries advance into the middle income range

does gnp have a unit root a re evaluation abstract stock and watson 1986 test the hypothesis that real per capita gnp has a unit root by using a test statistic due to phillips 1985 which incorporates a non parametric correction for the serial correlation induced by system and error dynamics the version of this test that is used by stock and watson does not accomodate the presence of a drift and to compensate they detrend the series by extracting a 1 5 annual trend growth we use a version of this class of non parametric tests developed by phillips and perron 1986 which allows for an estimated drift and reassess the stock and watson findings

social capital and loan repayment performance in northern vietnam this study analyses the effects of social capital on the loan repayment behavior of borrowers in vietnam in the context of agricultural economics an innovative data collection approach is used that originates from the field of sociology a personal network survey is carried out to measure the individual social capital of borrowers social capital variables are defined according to tie strength bonding bridging and social distance linking between the respondent and his her network member social capital has a significant and positive influence on the rescheduling of loans however we find no significant evidence for an effect of social capital on late payment of principal or interest

the climacteric in late victorian britain and france a reappraisal of the evidence the paper investigates the question of whether the trend rate of growth of gdp slowed down in britain or france in the nineteenth century we establish that real gdp belongs to the trend stationary process class of time series in each case rather than the difference stationary process and using kalman filter techniques analyse trends in a model incorporating time varying parameters without specifying breakpoints in advance we find contrary to the literature that neither country experienced a climacteric our results suggest that economic historians have been prone to exaggerated views of variations in trend economic growth

is there a slowdown in agricultural productivity growth in south america this article estimates agricultural productivity growth in 10 south american countries in 1969 2009 with the objective of investigating if the slowdown being measured in other countries is present in the region results show that productivity growth accounts for half of the three fold increase in agricultural output during this period and that performance is sensitive to r d investments in the sector the slowdown found for the 1990s to 2000s in the u s and some european economies does not seem to be present yet in south america the region s total factor productivity tfp growth rate increased steadily from 1 07 during the 1970s to 2 29 during the 2000s given lags in adoption and the adaptive nature of innovations in these economies we have yet to see the potential effects in south american agriculture of decreases in r d in advanced economies

land distribution and international agricultural productivity the unequal distribution of agricultural land is often cited as a source of inefficiency in agriculture previous cross country studies of agricultural productivity differences though have not considered land inequality this article addresses this issue by using cross country data on inequality in operational holdings of agricultural land from deininger and squire 1998 in an estimation of an agricultural production function the gini coefficient for land holdings is found to have a significant negative relationship with productivity this is consistent with the existence of heterogeneity in productivity by farm size within countries a one standard deviation drop in the gini coefficient implies an increase in productivity of 8 5

does output have a unit root new international evidence in this paper unit root tests for per capita output of 12 oecd countries are performed using traditional unit root tests it follows that the unit root hypothesis cannot be rejected except for the us however following the approach of perron 1989 which takes shifts in mean and or trend into account the null hypothesis of a unit root can be rejected in most countries in our sample in contrast to perron a method suggested by christiano 1992 is used to determine the break date endogenously

trust us to repay social trust long term interest rates and sovereign credit ratings this paper asks whether the sensitivity of market long term interest rates and credit ratings is associated with cross country differences in informal institutions measured by social trust we note a number of theoretical mechanisms that could imply that similar objective problems are more likely to be effectively dealt with in higher trust societies a set of panel estimates across middle and high income countries reveal that interest rates and ratings are substantially more sensitive to inflation and growth problems in low trust countries this finding sheds light on the differential market reactions to economic problems in seemingly comparable countries jel codes g12 a13

analysis of adoption and impacts of improved maize varieties in eastern zambia summary this paper analyzes the adoption and welfare impacts of improved maize varieties in eastern zambia using data obtained from a sample of over 800 farm households using both propensity score matching and endogenous switching regression models the paper shows that adoption of improved maize leads to significant gains in crop incomes consumption expenditure and food security results further show that improved maize varieties have significant poverty reducing impacts in eastern zambia the paper concludes with implications for policies to promote adoption and impacts of modern varieties in zambia

patterns of state productivity growth in the u s farm sector linking state and aggregate models this article focuses on agricultural productivity growth at both sector and state levels it does so in a way that preserves the economic integrity of national and state production accounts a model accounting for interstate transactions in farm goods links sectorwide and state specific measures of total factor productivity growth an interesting conclusion is that the smooth persistently positive trend typically observed for farm sector productivity growth masks considerable variation across states and regions the results also indicate that farm sector productivity growth is wholly a function of productivity trends in the individual states interstate shifts in production activity and resource reallocations have had little impact

testing household specific explanations for the inverse productivity relationship the inverse relationship between land productivity and farm size is an old and puzzling empirical regularity most explanations for this relationship rely on market imperfections that jointly determine the farm size and the household s shadow price of some productive inputs we use plot level data from the icrisat vls to assess whether these household specific theories can explain the puzzle the data exhibit plots of different sizes being simultaneously cropped by the same household the inverse relationship is shown to hold true with the same magnitude across the plots of each household thus cross household heterogeneity does not suffice to explain the puzzle