when do long run identifying restrictions give reliable results many recent articles have identified behavioral disturbances in vector autoregressions by imposing restrictions on the long run effects of shocks this article demonstrates that this approach will be unreliable unless the underlying economy satisfies three types of strong restrictions although many aspects of these issues have been raised before this article draws out and illustrates the implications for inferences under the long run scheme furthermore it provides strategies for dealing with the problems

an analytical model of farmers demand for replacement seed the purchase of new seed of a variety that a farmer is already growing varietal replacement in general and varietal choice during periods of rapid technological change are examples of seed replacement choices a seed replacement choice differs from decisions about other inputs such as fertilizer or labor in that seeds can be repro duced for the next crop season benefits from the purchase of new seed can continue for sev eral years and purchased seed is a self sustain ing input although it is subject to depreciation replacement seed is therefore in some ways analogous to a capital item rather than a variable input agricultural economists in general have considered only the analysis of varietal choice with rapid technological change theoretical nowshirvani and empirical herath har daker and anderson gafsi and roe studies of varietal choice tend to model the farmer s de cision as a single period portfolio allocation of land between modern and traditional varieties thus the attributes of interest are yield mo ments of the yield distribution and occasionally other varietal characteristics other approaches to analyzing farmers choice of seed technology emphasize how a related input fertilizer tube wells affects the level and riskiness of return feder 1980 1982 prices risk the lumpiness of the associated inputs and possible credit con straints determine the portfolio choice over time in these models in none of these approaches is the more general case of demand for replace ment seed explicitly recognized this paper proposes an analytical model of the demand for replacement seed the model describes the factors that induce a farmer to re place seed and the optimal frequency of new seed purchase given myopic and infinite time hori zons the model is applied to wheat seed de mand in pakistan conclusions limitations and possible extensions of the model are also con sidered

innovation and imitation adoption of cocoa by indonesian smallholders abstract this paper presents evidence on the role of copying in the diffusion of a new crop the evidence is based on rural surveys carried out by the first author in regions in indonesia where in the 1980s a new crop cocoa had been introduced quantitative estimates of the role of copying are obtained which are then used to simulate the effect of copying on the timing of adoption of the crop

on information and innovation diffusion a bayesian approach learning and information accumulation are hypothesized to play a major role in innovation diffusion for instance hiebert argues that the probability distributions of new and unfamiliar technological parameters as perceived by farmers will shift over time due to learning and experience probabilities will be redistributed from lower to higher payoffs this induces farmers to increase their use of the innovation which was new seed varieties in the hiebert model the model presented by kislev and shchoribachrach introduces in the new technology production function an efficiency factor which is positively related to learning it is approximated by the cumulative over time output produced with the innovative technology as learning increases the innovation becomes advantageous for more and more producers who then adopt it in a similar vein feder and o mara construct a diffusion process where uncertainty about an innovation high yielding varieties hyv depends on cumulative area allocated to hyv this represents experience with the accumulation of experience uncertainty declines and the innovation is adopted by an increasing proportion of producers these models produce sensible and empirically valid hypotheses about the dynamics of innovation diffusion however the accumulation of information which is the basic driving element in these models is not treated explicitly thus the use of cumulative output or a cumulative input as an index of learning while plausible still requires formal justification one possibility is a bayesian learning process indeed the work by o mara 1971 1981 and more recently by lindner fischer and pardey have utilized bayes theorem to characterize an individual farmer s adoption behavior

economic determinants of the nominal treasury yield curve abstract macroeconomic shocks account for most of the variability of nominal treasury yields inducing parallel shifts in the level of the yield curve we develop a new approach to identifying macroeconomic shocks that exploits model based empirical shock measures technology shocks shift yields through their effect on expected inflation and the term premium shocks to preferences for current consumption affect yields through their impact on real rates and expected inflation for both shocks the systematic reaction of monetary policy is an important transmission pathway we find little evidence that fiscal policy shocks are an important source of interest rate variability

adoption of a politicized technology bst and wisconsin dairy farmers technologies that are the focus of extensive public debate prior to commercialization may have diffusion paths which are distinct from the classic sigmoid shape often used by economists descriptive and econometric analysis of ex ante and ex post data on bovine somatotropin use by wisconsin dairy farmers reveal that this controversial technology has a relatively low adoption rate and little prospect for adoption growth in the near future further research on potential adoption outcomes for technologies that are politicized prior to commercialization could improve economists predictive capacities

the effects of expectations on technology adoption some empirical evidence n rosenberg 1976 argues that in many markets prospective buyers for an innovation are strongly influenced by expectations concerning the timing and significance of future improvements the primary objectives of this article are to provide a model of the innovation decision process of user firms that expect improvements in current best technology and to offer an empirical study that tests the model s predictions among other results the author finds empirical support for rosenberg s argument and demonstrates theoretically that compared to models without technological expectations and learning the optimal decision process is nonmonotonic copyright 1994 by blackwell publishing ltd

technology adoption and agricultural price policy market interventions such as price supports or fertilizer subsidies can lead to gains from speeding up adoption of new technologies but the policies distort resource allocation a framework is developed for optimizing policies in light of the adoption allocation trade off based on adoption coefficients and production parameters from third world agriculture levels and duration of policies are estimated sensitivity analyses are performed gains are small at best and may be zero or negative in view of farmer costs of adjustment and deadweight losses from taxes profit technology adoption if new technologies are desirable why not use price supports or input subsidies to encourage faster technology adoption while frequently raised in policy deliberations this question has received little serious analysis particularly neglected has been the conflict or trade off between a gains in output as producers switch from old to new technologies and b the losses from resource use distortions brought about by price policies when output prices are raised or prices of inputs such as fertilizer are lowered the

the demand for information and the diffusion of a new product abstract the paper examines the implications of the ability of a consumer to learn about the characteristics of a new product on the diffusion of the product over time the demand for information by the consumer is shown to generate a sigmoid diffusion curve for total sales of the product further it is shown that over time the elasticity of demand along the diffusion curve increases

news shocks and the slope of the term structure of interest rates abstract we adopt a statistical approach to identify the shocks that explain most of the fluctuations of the slope of the term structure of interest rates we find that one shock can explain the majority of unpredictable movements in the slope impulse response functions lead us to interpret this shock as news about future total factor productivity tfp by showing that slope shocks are essentially tfp news shocks we provide a new explanation for the relationship between the slope and macroeconomic fundamentals our results also provide a new empirical benchmark for structural models at the intersection of macroeconomics and finance jel e23 e43 e52 g12 g14

technology adoption under price uncertainty abstract the paper examines the impact of changes in the variance of output prices on the bias and intrafirm diffusion rate of technological change the results indicate that a reduction in the variance of output prices will increase the rate of adoption and the intrafirm diffusion speed of yield increasing technologies the opposite is true for cost reducing technologies

dynamics of variety change on wheat farms in pakistan a duration analysis abstract decades after the green revolution sustaining wheat productivity remains an important policy goal for the government of pakistan understanding the speed of diffusion of new wheat varieties can contribute to this goal we apply duration analysis to identify the factors that shorten the time until a farmer replaces one modern variety by another and test hypotheses concerning two recurring themes of the green revolution farm size differences and the role of information sources in seed diffusion we find that time to adoption averages only 4 years but is shorter on larger farms factors that speed variety change also differ by farm size extension and media sources of information significantly influence adoption among larger farmers relative to information gained through social relationships but this is not the case for marginal farmers traits related to consumption quality speed adoption on smaller wheat farms where families both sell and consume their wheat higher yields drive adoption for the most subsistence oriented marginal group

news driven business cycles insights and challenges there is a widespread belief that changes in expectations may be an important independent driver of economic fluctuations the news view of business cycles offers a formalization of this perspective in this paper we discuss mechanisms by which changes in agents information due to the arrival of news can cause business cycle fluctuations driven by expectational change and we review the empirical evidence aimed at evaluating their relevance in particular we highlight how the literature on news and business cycles offers a coherent way of thinking about aggregate fluctuations while at the same time we emphasize the many challenges that must be addressed before a proper assessment of the role of news in business cycles can be established jel d83 d84 e13 e32 o33

a macro finance model of the term structure monetary policy and the economy this paper develops and estimates a macro finance model that combines a canonical affine no arbitrage finance specification of the term structure with standard macroeconomic aggregate relationships for output and inflation from this new empirical formulation we obtain several interesting results 1 the latent term structure factors from finance no arbitrage models appear to have important macroeconomic and monetary policy underpinnings 2 there is no evidence of monetary policy inertia or a slow partial adjustment of the policy interest rate by the federal reserve and 3 both forward looking and backward looking elements play important roles in macroeconomic dynamics

are there spatial spillovers in the adoption of clean technology the case of organic dairy farming this paper examines spatial spillovers associated with the adoption of organic dairy farming we hypothesize that neighboring farmers can help to reduce the uncertainty of organic conversion by lowering the fixed costs of learning about the organic system a spatially explicit 10 year panel dataset of more than 1 900 dairy farms in southwestern wisconsin is used as input into a reduced form econometric model of the decision to convert to organic production using an identification strategy that exploits the panel aspect of the micro dataset we find evidence that the presence of neighboring organic dairy farms affects the conversion decision

news shocks and business cycles abstract this paper proposes and implements a novel structural var approach to the identification of news shocks about future technology the news shock is identified as the shock orthogonal to the innovation in current utilization adjusted tfp that best explains variation in future tfp a favorable news shock leads to an increase in consumption and decreases in output hours and investment on impact more suggestive of standard dsge models than of recent extensions designed to generate news driven business cycles though news shocks account for a significant fraction of output fluctuations at medium frequencies they contribute little to our understanding of recessions

social network effects on the extent of innovation diffusion a computer simulation of innovation diffusion no longer focus exclusively on explaining the rate at which innovations diffuse or the sequence in which they are adopted they also focus on explaining why certain innovations diffuse extensively be coming de facto standards whereas others do so partially or not at all many of these theories specify a bandwagon process a positive feedback loop in which increases in the number of adopters create stronger bandwagon pressures and stronger bandwagon pressures in turn cause increases in the number of adopters factors affecting if and how many times this feedback loop cycles explain if and how many potential adopters jump on a bandwagon we argue that one important factor has not yet been incorporated into theories explaining bandwagons extent the structure of social net works through which potential adopters of innovations find out information about these innovations which can cause them to adopt these innovations we advance a theory of how the structure of social networks affects bandwagons extent we propose that both the number of network links as well as small seemingly insignificant idiosyncracies of their structures can have very large effects on the extent of an innovation s diffusion among members of a social network

the family as the health producer when spouses act strategically the grossman model has been extended recently in order to take account of the fact that most people lead their lives in a family using frameworks in which family members respectively a have common preferences and b are nash bargainers these models however do not consider individual incentives for behaving strategically in the model presented in this paper spouses interact strategically both in the production of own health and in the production of health of other family members we analyse inter alia the impact on the distribution of health of changes in family policies such as child allowance and custody rules

adoption of high yielding rice varieties in bangladesh an econometric analysis abstract in this paper we build two logistic type econometric models to explain hyrv diffusion rate in bangladesh long run potentials ceiling diffusion rates and the effects of other economic variables on the adoption path are determined simultaneously within the model results from our final model indicate that the diffusion rate is not constant over time furthermore rate and level of adoption are found to be influenced by flood damage jute rice price ratio and hyrv local rice variety price ratio an important outcome of our analysis is that the ceiling adoption level for bangladesh has nearly been reached unless new hyrvs are developed with wider adaptability especially for drought and flood prone areas little scope exists for production increases through hyrv acreage expansion this conclusion has significant policy implications for agricultural planners and development agents in bangladesh

bond yields and the federal reserve bond yields respond to policy decisions by the federal reserve and vice versa to learn about these responses i model a high frequency policy rule based on yield curve information and an arbitrage free bond market in continuous time the fed s target is a pure jump process jump intensities depend on the state of the economy and the meeting calendar of the federal open market committee the model has closed form solutions for yields as functions of a few state variables introducing monetary policy helps to match the whole yield curve because the target is an observable state variable that pins down its short end and introduces important seasonalities around fomc meetings the volatility of yields is snake shaped which the model explains with policy inertia the policy rule crucially depends on the two year yield and describes fed policy better than taylor rules

explorations into factors explaining money market returns in this article we measure and interpret the common factors that describe money market returns results are presented for both three and four factor models we find that the three factor model explains on average 86 percent of the total variation in most money market returns while the four factor model explains on average 90 percent of this variation using mimicking portfolios we provide an interpretation of the systematic risks represented by these factors in this article we attempt to measure and interpret the common factors that describe money market returns the factor approach we employ assumes that the covariance matrix of a set of random variables in this case excess returns can be decomposed into common or systematic components and idiosyncratic or nonsystematic components this decomposition into systematic and nonsystematic components is based on an assumption of a linear relationship between the returns of each security and a set of common factors this is the assumption of linear return generating models which form an integral part of the structure of many asset pricing theories for example arbitrage pricing theory apt as developed by ross 1976 the interpretation is that the common factors represent sources of systematic or nondiversifiable risk and the idiosyncratic component of returns represents diversifiable risks our focus here is not on testing a particular asset pricing model per se but on developing empirical evidence for the existence of stylized facts regarding money market returns the stylized facts take the form of the existence measurement and interpretation of the common factors that are found in money markets our attempt to measure and interpret these sources of systematic risk may eventually lead to the construction of observable eco

on the term structure of interest rates abstract this paper tests the one good stochastic growth model with respect to its ability to explain the term structure of real interest rates we undertake both a qualitative and quantitative analysis first we assess the changing shape of the yield curve over the model economy s business cycle and compare our results with what is empirically observed second we employ the model to study various implications of informational and allocative efficiency properties which the artificial economy must possess it is found for example that long term rates are less volatile than short term rates and that holding premia can be highly correlated over time third we study the time varying risk premium implicit in the economy s forward rate structure a purely quantitative assessment of the model s explanatory power is also provided

the term structure of interest rates in real and monetary economies abstract this paper modifies standard asset pricing models by introducing capital a variable labor supply and money a surprising but very positive result is that in a real production economy the interest rate is close to a random walk this result is found to be true even if there is no persistence in the driving process of the model in this paper we generalize the standard cash in advance constraint by using a shopping time technology this generalization makes it possible to match observed variability for the velocity of money this type of monetary model however is not successful in matching observed behavior of bond prices