impact of modern agricultural technologies on smallholder welfare evidence from tanzania and ethiopia this paper evaluates the potential impact of adoption of improved legume technologies on rural household welfare measured by consumption expenditure in rural ethiopia and tanzania the study utilizes cross sectional farm household level data collected in 2008 from a randomly selected sample of 1313 households 700 in ethiopia and 613 in tanzania the causal impact of technology adoption is estimated by utilizing endogenous switching regression this helps us estimate the true welfare effect of technology adoption by controlling for the role of selection problem on production and adoption decisions our analysis reveals that adoption of improved agricultural technologies has a significant positive impact consumption expenditure in per adult equivalent terms in rural ethiopia and tanzania this confirms the potential role of technology adoption in improving rural household welfare as higher consumption expenditure from improved technologies translate into lower poverty higher food security and greater ability to withstand risk an analysis of the determinants of adoption highlighted inadequate local supply of seed access to information and perception about the new cultivars as key constraints for technology adoption

the tree cutting problem in a stochastic environment the case of age dependent growth abstract harvest policies are derived for growing biological assets e g forests livestock subject to stochastic age dependent growth and price uncertainty the task posed is analyzed as a continuous time optimal stopping problem for diffusion processes both single and ongoing rotation problems are considered qualitative comparative static and numerical results are provided

the development of urban labour markets china s urban wage curve 1980 92 this study explores the effect of china s economic reforms and growth on a critical outcome of labour market interactions wage levels provincial data from 1980 to 1992 are used to analyse changes in interregional wage differentiation and the relationship between average and real wages and a variety of economic variables the results illuminate the increasing role of market forces particularly labour demand variables such as economic growth and foreign investment in determining wage levels and explaining the pattern of first declining and then sharply rising interregional wage differentials in the 1980s and early 1990s at the same time the empirical results highlight the persistence of barriers to labour mobility across regions and enterprises of different ownership types these findings suggest that the evolution of china s urban labour market to date is marked by a combination of unprecedented flexibility as well as old and new forms of rigidity

economies of scale and the optimality of rotational dynamics in forestry forest harvesting is traditionally analyzed in terms of the faustmann rotation model this paper considers the identification of optimal forest harvest regimes using jump controls this approach enables the structural assumptions of clear cut technology and identical cycles in perpetuity which are imposed in a faustmann model to be relaxed jump control models permit investigation of the biological and economic conditions which favour continuous growth management regimes as opposed to clear cut harvest regimes a numerical solution approach to the jump control model is presented the link between the harvest cost function and the optimal biomass path is analyzed economies of scale are shown to generate rotational harvest as optimal policies

virtual price approach to short term timber supply under credit rationing abstract duality and virtual prices are used in a fisherian two period savings consumption model to simplify the analysis of nonindustrial private timber supply under credit rationing a possible way to measure the degree of credit rationing perceived by nonindustrial private forest owners is proposed slutsky type decompositions for the derivatives of the credit rationed timber supply function are calculated and the credit rationed derivatives are related to corresponding derivatives in a perfect capital market further the impact of the degree of credit rationing on the substitution and income effects of the exogenous variables are discussed and it is shown that the total effects are independent of the degree of credit rationing the results help to interpret parameter estimates of private nonindustrial timber supply functions especially if micro data are available

real wages over the business cycle evidence from panel data one topic on which keynes did not disagree with classical economists was the cyclical behavior of real wages keynes 1936 as well as various classical writers predicted that real wages should move countercyclically quoting the general theory p 17 in general an increase in employment can only occur through the accompaniment of a decline in real wages thus i am not disputing this vital fact which the classical economists have rightly asserted as indefeasible this prediction is based on the premise of competition and a given short run capital stock increases in employment then correspond to more intensive use of capital and through diminishing product lower real wages for this reason evidence by dunlop 1938 and tarshis 1939 that real wages move procyclically was viewed as paradoxical both dunlop and tarshis based their findings on an observed positive correlation between real and money wages which given the procyclical movement of money wages implies a positive correlation between

business cycle models aggregation and real wage cyclicality a substantial literature has developed to estimate the true cyclicality of real wages that is composition bias free two major issues are addressed in this article aggregation of heterogeneous workers and potential bias in the measurement of the labor input a general analysis of the biases is presented and alternative approaches in the literature are nested in a single framework estimates based on an efficiency units concept that avoids the usual aggregation problems are presented composition bias underestimates the usual parameters of interest unless both the price and the quantity of the labor input are adjusted appropriately

wage flexibility in the chinese labour market 1989 2009 abstractwage flexibility in the chinese labour market 1989 2009 regional studies china s bureaucratic wage determination system is gradually being replaced by a market based system leading to a novel version of a dual labour market this paper studies wage flexibility in this dual market its principal findings are as follows wages in both sectors have become less responsive to changes in official registered unemployment with an alternative market based measure of unemployment becoming more relevant there is evidence of convergence of flexibility between the two sectors the wages of women exhibit greater flexibility than those of men and there is evidence of differences in wage flexibility between workers who have urban residential rights and rural migrants

on the faustmann solution to the forest management problem abstract this paper is concerned with optimal solutions to the forest management problem when future utilities are undiscounted by examining asymptotic properties of such solutions we find that i if the utility function is linear then the faustmann periodic solution is optimal ii if the utility function is increasing and strictly concave an optimal solution converges to the maximum sustained yield solution which we characterize as a golden rule these results may be viewed as a possible resolution to the debate in forestry economics about what constitutes an optimal policy in forest management

reform without losers an interpretation of china s dual track approach to transition this paper develops a simple model to analyze the dual track approach to market liberalization as a mechanism for implementing efficient pareto improving economic reform that is reform achieving efficiency without creating losers the approach based on the continued enforcement of the existing plan while simultaneously liberalizing the market can be understood as a method for making implicit lump sum transfers to compensate potential losers of the reform the model highlights the critical roles of enforcement of the plan for achieving pareto improvement and full liberalization of the market track for achieving efficiency we examine how the dual track approach has worked in product and labor market liberalization in china

wage flexibility in regional labour markets evidence from italy and germany ammermuller a lucifora c origo f and zwick t wage flexibility in regional labour markets evidence from italy and germany regional studies this paper investigates the functioning of regional labour markets in italy and germany for different employee groups and regions it derives theoretical hypotheses on group specific correlations between regional unemployment and individual wages distinguishing between regions using micro data matched to local unemployment rates wage equations are specified and empirically tested for italy no evidence is found in favour of a relationship between wages and local unemployment in germany results appear to be sensitive to model specification and type of employees in both countries the reaction of wages to local unemployment varies significantly along the wage distribution being more sensitive around median quantiles ammermuller a lucifora c origo f et zwick t la flexibilite des salaires dans les marches du travail regionaux des preuves provenant de

a stochastic analysis of the tree paradigm abstract the tree paradigm which is a problem in optimal stopping has important ramifications for human capital acquisition search behavior firm entry and in the theory of renewable resources our paper extends previous work in the stochastic literature on several fronts we exhibit a tractable solution to the rotation problem for the stochastic model analyze the effects of inputs which control the growth process and illustrate our results with a multi stage learning problem

the wage curve a review in the wage qurve david g blancflower and andrew j oswald argue that there is a fundamental negative relation between wages and the unemployment rate in a worker s local labor market blancflower and oswald use large scale micro data sets to estimate this relation for the united states britain and 10 other countries i review their empirical methods and findings and provide some further evidence on the nature of the wage curve relationship in the united states i conclude that there is a strong statistical correlation between rates of pay and local unemployment although the interpretation of this correlation remains unresolved this abstract was borrowed from another version of this item

cooperation harassment and involuntary unemployment an insider outsider approach the authors present a theory of involuntary unemployment which explains why the unemployed workers outsiders are unable or unwilling to find jobs even though they are prepared to work for less than the prevailing wages of incumbent workers in siders the outsiders do not underbid the insiders since were the y to do so the insiders would withdraw cooperation from them making their work unpleasant with harassment and thereby reducing the prod uctivity and increasing the reservation wages of the underbidders th e resulting labor turnover costs create economic rent which the insid ers tap in wage setting and as a result involuntary unemployment ma y arise copyright 1988 by american economic association

real wage cyclicality of job stayers within company job movers and between company job movers using the british new earnings survey panel data nespd for the period 1975 to 2001 we estimate the wage cyclicality of job stayers those remaining within single jobs in a given company within company job movers and between company job movers we also examine how the proportion of internal and external job moves varies over the business cycle we find that the wages of internal movers are slightly more procyclical and wages of external movers considerably more procyclical than those of stayers notwithstanding a decomposition shows that in britain wage cyclicality arises almost entirely from the procyclicality of wages for job stayers with across and within firm mobility playing a lesser role thus there is little evidence for rigid wage models that imply that employers use changes in job titles as a means of adjusting wages to the business cycle we also show that the distinctions between private and public sectors and between workers covered and uncovered by collective agreements have important impacts on the wage estimates of both stayers and movers

optimal forest rotation and land values under a borrowing constraint abstract this study relaxes the assumption of perfect capital markets in the classical faustmann forest rotation model a constraint on borrowing changes all the basic properties of optimal forest harvesting instead of a constant rotation period an infinite chain of rotations is determined by a nonlinear difference equation the rotation period evolves over time and approaches a stationary rotation in finite or infinite time the length of optimal rotation timber supply and the value of forest land depend on forest owner specific factors that are normally nonexistent in rotation problems the model explains several empirical findings that cause problems for the classical versions of the faustmann model

the cyclicality of real wages within employer employee matches using data from the panel study of income dynamics the author examines the cyclicality of wages within employer employee matches for the years 1970 91 recent research on wage cyclicality has suggested that wages are very procyclical tending to rise and fall with economic upturns and downturns even for workers who remain with the same employer the author finds however that the evidence for wage procyclicality within the matches he examines is rather weak except for the small group of workers who were paid by piece rate or commissions despite having acyclical wage rates men who were paid hourly had earnings movements that were very procyclical salaries exhibited little cyclicality but salaried workers who had income sources from bonuses commissions or overtime had procyclical earnings the results suggest that the increasing prevalence of incentive based pay will increase the procyclicality of wages within matches

on equilibrium cycles and normal forests in optimal harvesting of tree vintages abstract a normal forest that has an even land allocation between tree vintages has traditionally been taken as a desirable long run goal in forestry in contrast the presently favored economic hypothesis suggests that under positive discounting the optimal forest vintage structure typically evolves to a cycle without convergence toward the normal forest this paper proves the existence of the cyclical solution and its global stability properties using elementary methods the occurrence of cycles in forest harvesting is given a resource economics interpretation a numerical example that was previously analyzed incorrectly is clarified in the existing vintage model forest land has no competing uses in an extension with competitive land use the stationary cycles are shown to be replaced by a saddle point path with damped oscillations and convergence toward the normal forest

optimal forest rotation with in situ preferences abstract this study develops a utility maximization infinite horizon forest rotation model that includesin situvalues and the forest owner s consumption savings decision making the value of forest land becomes owner specific and depends on property rights related toin situbenefits the length of the rotation period depends e g on the wealth of the forest owner and may evolve in time a forest owner with accumulating nonforest assets never continues harvesting forever in contrast with decreasing nonforest assets the rotation period converges toward the faustmann solution in a multiple stand version of the model the harvesting decisions regarding different stands are linked together via the budget constraint and the dependence of an individual stand sin situvalue on the age structure of the whole forest numerical simulation with two stands suggests that within the class of concavein situvaluation functions the optimal solution yields convergence toward forests with increasing heterogeneity of age structures

on the elasticities of harvesting rules abstract in this paper we rank the relative importance of the exogenous parameters upon the optimal harvesting size in a stochastic rotation problem we show that when the tree growth follows geometric brownian motion the harvesting size is most elastic to the harvesting cost followed by the interest rate and is least elastic to the parameters of tree growth similar ranking holds for the linear growth case in both cases the harvesting size is increasing and concave in the harvesting cost bounded between two parallel lines the harvesting decision is made according to a stochastic extension of the faustmann formula

measuring wage flexibility the case of turkey before and after structural adjustment this article presents an empirical analysis of wage flexibility in the formal private sector in turkey the analysis is based on a wage bargaining model that links the nominal wage demands to labour market conditions which are proxied by the rate of unemployment productivity improvements and price expectations the model is estimated on the basis of panel data of the formal private manufacturing industry and changes in the wage setting mechanism as the country shifts from an import substituting industrialization strategy to an export oriented growth regime are discussed this debate is particularly important in terms of its policy implications and is relevant to current international discussions of the role of labour markets during structural adjustment in most economic policy discussions unemployment is assumed to be a labour market rigidity problem the results of this article however suggest that increased flexibility of wages leaves little room for such arguments in the light of these findings the prospect of wage rigidity becomes immaterial and a focus on the structural problems of the economy which are outside the labour market becomes central

efficiency wage models of unemployment keynesian economists hold it to be self evident that business cycles are characterized by involuntary unemployment but construction of a model of the cycle with involuntary unemployment faces the obvious difficulty of explaining why the labor market does not clear involuntarily unemployed people by definition want to work at less than the going wage rate why don t firms cut wages thereby increasing profits

the german wage curve evidence from the iab employment sample abstract this paper examines the german wage curve using the institut fur arbeitsmarkt und berufsforschung iab employment sample over the period 1981 1990 a random sample of 6590 employees covering 142 labor market regions over a ten year period is considered the total number of observations is 40 852 taking into account the endogeneity of unemployment as well as controlling for region and time effects this paper finds support for the wage curve in germany the overall unemployment elasticity estimate is 0 07 and is higher for younger workers than older workers the wages of less qualified workers are more responsive to local unemployment rates than the wages of more qualified workers also the wages of men are slightly more responsive to local unemployment rates than the wages of women ignoring endogeneity of the local unemployment rate yields results in favor of the wage curve only for younger and less qualified workers accounting for endogeneity of the unemployment rate yields evidence in favor of the wage curve across all types of workers

bequests credit rationing and in situ values in the faustmann pressler ohlin forestry model the problem of determining the optimal time to stop the pure aging process has a 150 year history in forestry the success of the rotation model lies in the fact that it is taken to be theoretically sound empirically testable and has clear practical relevance nonetheless empirical findings show that timber supply depends on variables missing from the original formulation previous research has addressed the problem by abandoning the pure aging description of forests this study demonstrates that the optimal aging process becomes forest owner specific under imperfect land and capital markets and if the owner has in situ preferences

the stochastic rotation problem a generalization of faustmann s formula to stochastic forest growth abstract in the present paper we study the optimal cutting strategy 1 2 for an ongoing forest by using stochastic impulse control we show how faustmann s formula can be generalized to stochastic growing forests the paper extends and clarifies previous studies by miller and voltaire 1983 clarke and reed 1989 and reed and clarke 1990