testing for behavioral objective and aggregation opportunities in u s agricultural data to guide formulation of an aggregate model of u s agricultural production this paper reports nonparametric test results for both behavioral objective and aggregation level nonparametric tests are implemented as heuristics to determine empirical support for simplified analytical structures evidence does not refute the joint hypothesis that producers behave collectively as though they are a price taking profit maximizing firm with a convex technology subject to nonregressive technical change the empirical results also support exhaustive aggregation of input categories but much less aggregation of outputs this paper reports the first known implementation of the nonparametric homothetic separability tests

farmers investment behavior an empirical assessment of two specifications of expectations the capital investment decision is modeled and two different assumptions about expectations are compared and tested using panel data for dutch dairy farms the utilization of panel data allowed to account for the possibility that the intercept in the function for capital varies over the farms the models are estimated using the generalized method of moments gmm for dynamic panel data the model based on static expectations fits the data well the results obtained from the rational expectations model are not consistent with the theory

demand systems with nonstationary prices relative prices are nonstationary and standard root t inference is invalid for demand systems but demand systems are nonlinear functions of relative prices and standard methods for dealing with nonstationarity in linear models cannot be used demand system residuals are also frequently found to be highly persistent further complicating estimation and inference we propose a variant of the translog demand system the ntlog and an associated estimator that can be applied in the presence of nonstationary prices with possibly nonstationary errors the errors in the ntlog can be interpreted as random utility parameters the estimates have classical root t limiting distributions we also propose an explanation for the observed nonstationarity of aggregate demand errors based on aggregation of consumers with heterogeneous preferences in a slowly changing population estimates using u s data are provided

nonparametric estimation of sample selection models sample selection models provide an important way of accounting for economic decisions that combine discrete and continuous choices and of correcting for nonrandom sampling nonparametric estimators for these models are developed in this paper these can be used for estimating shapes and important economic quantities as in standard nonparametnc regression endogeneity of regressors of interest is allowed for series estimators for these models are developed which are useful for imposing additivity restnctions that arise from selection corrections convergence rates and asymptotic normality results are derived an application to returns to schooling among australian young females is given

on the indeterminacy of capital accumulation paths abstract in neoclassical optimal growth models the stability of the accumulation paths depends on the discount parameter we prove that for discount factors small enough the policy function which describes an optimal path can be of any type the result is achieved using the notion of concavity we adopt a constructive approach given any twice differentiable map we show how to construct an optimal growth problem which produces that map as the optimal policy function a consequence is that chaos can appear in these models we also provide bounds on the values of the discount parameter for which indeterminacy is possible

estimating theoretically consistent demand systems using cointegration techniques with application to greek food data abstract the use of time series techniques cointegration and error correction models has been offered as a potentially promising way in estimating demand systems that resolve the perennial issue of violating the theoretical postulates of homogeneity and symmetry the empirical results of this paper based on linearized aids and greek food data indicate that sample size aggregation schemes and model specification seem to be important factors in the estimation of a theoretically consistent demand system they also show that homogeneity is sensitive to sample size while symmetry is sensitive to the aggregation scheme adopted

price effects on compound commodities we examine the effect of simultaneous price changes on the total demand for a group of goods which we call a compound commodity specifically we consider unit and proportional cost components e g taxes transportation costs imposed on compound commodities if the unit cost is positive then the proportional cost raises the relative price of the more expensive good and thus induces substitution towards the less expensive good within this group then the substitution effect of the proportional cost for a compound commodity is non negative if and only if the compound commodity and the other goods are on average not strongly substitutable

structural change capital investment and productivity in the food processing industry investment in new technology affects structural change and economic performance through its effect on capital and input composition this is particularly important for capital intensive industries such as food processing which lack short run flexibility due to adjustment costs this study considers the impacts of capital quasi fixity on capital and noncapital input decisions made in the u s food and kindred products industry from 1965 to 1991 a cost based production theory model is used to evaluate investment motivations for three capital components productivity growth accompanying changing input patterns is then discussed focusing on capital and farm input demand

possibilities for including the opportunity cost of time in recreation demand systems recreation demand modelers have attempted to identify and incorporate the opportunity cost of an individual s time in travel and on site in the model larson 1993b focused on the value of leisure time in a model where individuals face a fixed work week in this paper we examine the connection between labor supply and recreation demands and focus on conditional demand systems we illustrate that corner solution models are not needed to explain several interesting time related recreation issues

on behavioral complementarity and its implications we study the behavioral definition of complementary goods if the price of one good increases demand for a complementary good must decrease we obtain its full implications for observable demand behavior its testable implications and for the consumer s underlying preferences we characterize those data sets which can be generated by rational preferences exhibiting complementarities the class of preferences that generate demand complements has leontief and cobb douglas as its as extreme members

from the crowd to the market the role of reward based crowdfunding performance in attracting professional investors abstract we focus on new technology based entrepreneurial ventures engaging in reward based crowdfunding and examine the effect of their performance in such funding channel on the likelihood of securing subsequent funding from professional investors we also study how this effect is influenced by the presence of patents granted for the new product idea and the entrepreneur social capital results from a sample of technology projects launched on kickstarter demonstrate that pledging a higher amount of money in crowdfunding can ignite professional investors interest and thus help secure subsequent funding however this positive evidence is effective only when complemented by the presence of patents or a large network of social ties

a decomposition of total factor productivity growth the case of chinese agricultural growth before and after reforms our objective in this paper is to explain a method to decompose the sources of total factor productivity tfp growth into technological progress and changes in technical efficiency within the framework of the varying coefficients frontier production function an empirical application is demonstrated using the chinese provincial level agricultural data covering the period 1970 87 the results indicate that tfp growth in the prereform period was negative in twenty out of twenty eight provinces and that it was positive in almost all provinces during the reform periods while negative in sixteen out of twenty eight provinces in the postreform periods of 1984 87

government as fund of fund and vc fund sponsors effect on employment in portfolio companies governments around the world have set up fund of fund programs to increase the supply of venture capital financing to young growth oriented firms in these programs a government fund of fund acts as limited partner in a venture capital fund the venture capital investment process is hereby delegated to external investors which were selected by the government fund of fund we investigate employment growth in 108 portfolio companies that benefited from the arkimedes fund of fund in flanders accounting for the heterogeneity in the types of venture capital investors managing hybrid funds and the associated goal diversity and resource endowments we find that portfolio companies backed by hybrid independent venture capital funds show greater employment growth than those backed by hybrid captive or hybrid government venture capital funds this finding is relevant because it indicates that the financial objectives of hybrid independent venture capital funds are highly compatible with the government s objective of employment growth as providing companies with superior monitoring and value adding services with the objective of realizing a successful exit creates employment in the process

wealth inequality preference heterogeneity and macroeconomic volatility in two sector economies we explore the link between wealth inequality preference heterogeneity and macroeconomic volatility in a two sector neoclassical growth model first we prove that if agents have homogeneous preferences when the absolute risk tolerance is a strictly convex concave function sufficiently high low levels of wealth inequality may lead to endogenous fluctuations in the neighborhood of the steady state second we consider the effects of preference heterogeneity when agents are homogeneous with respect to their wealth we show that when the utility function belongs to the hara class sufficiently high levels of preference heterogeneity may lead to endogenous fluctuations in the neighborhood of the steady state if the elasticity of intertemporal substitution in consumption is greater than one

a shadow price frontier measurement of profit efficiency in chinese agriculture a shadow price profit frontier model is developed to examine production efficiency of chinese farm households the model incorporates price distortions but retains the advantages of stochastic frontier properties the shadow prices and shadow profit are derived through a behavioral profit function empirical results using household survey data show that the conventional assumption of profit maximization based on market prices is inappropriate farmers resource endowment and education influence their allocative efficiency family size per capita net income and family members operating as village leaders are positively related to households production efficiency reducing market distortions should increase farm households production efficiency

discounting and long run behavior global bifurcation analysis of a family of dynamical systems abstract this paper is concerned with the relationship between the discount rate and the nature of long run behavior in dynamic optimization models the theory is developed under two conditions the first is history independence which rules out multiple limit sets the second is a condition that avoids the reversion to a stable steady state as the discount factor is lowered once cycles have emerged these conditions appear to be the minimal restrictions that would allow analysis by a bifurcation diagram the results are illustrated by two well known examples in this literature due to sutherland and weitzman samuelson journal of economic literature classification numbers c61 d90 041

european market integration for gas volume flexibility and political risk this is a copy of an article originally published by elsevier in energy economics see http www sciencedirect com science journal 03014215 2002 elsevier science b v

supply and demand functions for multiproduct u s cash grain farms biases caused by research and other policies this study presents new estimates of supply and demand elasticities for u s multiproduct cash grain farms and estimates of input and output bias effects caused by public and private crop research extension and farmers schooling the study also shows that the social rate of return to public crop research is large about 62 percent

aggregation without separability tests of the united states and mexican agricultural production data the generalized composite commodity theorem gcct and testing procedure is extended to test for consistent aggregation of the united states and mexican agricultural production data in each category for which earlier tests rejected homothetic separability nonrejected gcct and separability hypotheses provide empirical support for aggregating all the united states agricultural outputs into as few as two categories crops and livestock mexican agricultural outputs also can be aggregated into as few as two categories support for aggregating all outputs into a single category is ambiguous in both countries and is only provided by the gcct

exports and labor demand searching for functional structure in multi output multi skill technologies to simplify the representation of a technological relationship between inputs and outputs a production unit s technology must typically satisfy some restrictive conditions some of them being well known in the literature this article presents new results for aggregating labor inputs and outputs in terms of restrictions on elasticities of scale and substitution these conditions are then empirically investigated in a framework that is flexible and does not lose its flexibility after separability being imposed the empirical findings of the exact approach to aggregation are found to be rather pessimistic on the possibility of providing a simplified representation

founder s human capital external investment and the survival of new high technology ventures the effect of founder characteristics in attracting external investment and enhancing survival of new high technology ventures is explored using human capital theory and signalling theory we test the effect of founder characteristics on external investment in and survival of new high technology ventures by tracking a random sample of 193 high technology start ups all participants in the israeli technology incubator program founder s business management expertise and academic status attracted external investment but founder s general technological expertise did not founder s business management expertise and general technological expertise positively affected venture survival but founder s academic status did not possible implications for entrepreneurs investors policy and further research are discussed

the diminishing signaling value of patents between early rounds of venture capital financing a long stream of research has documented the positive effects that patents bring about to emerging firms in high technology industries the general consensus is that patents contribute to firm growth because they confer monopolistic market rights offer protection from competitors increase the negotiating position of patent holders and other benefits what has received relatively less attention in the literature is whether patents act as a signal that attracts investors such as venture capital firms the handful of studies that have addressed that question has not analyzed whether the signaling function of patents decreases after the initial attraction of venture capital as information asymmetries between investors and target firms reduce in this study we hypothesize that patent activity has a signaling value that diminishes once information asymmetries between investors and funded firms lessen to study our proposition we draw upon a longitudinal dataset of more than 580 u s based biotechnology firms to empirically demonstrate that biotechnology firms that have submitted patent applications substantially increase the level of funding they receive for their first round of financing in line with a reduction of information asymmetries once the initial investment has materialized patent applications and granted patents have no effect on the growth of venture capital funds raised during the second round of financing we conclude the study with a discussion of avenues for new research implications for policy makers that consider the usefulness of the current patent system and with insights that can be employed by managers of firms in knowledge intensive areas such as biotechnology

wealth distribution and output fluctuations we explore the link between wealth inequality and output fluctuations in a general two sector neoclassical growth model with endogenous labor and heterogeneous agents when agents have homogeneous crra preferences and individual wealth is pareto distributed a sufficiently large rise in the gini index typically leads to an increase in endogenous fluctuations of output for general economies we show that under plausible conditions on the fundamentals wealth inequality is still a destabilizing factor

variation in retail costs for fresh vegetables and salty snacks across communities in the united states abstract households living in different communities pay different amounts of money for food food costs depend on whether a household lives in an urban community or in a locality with a high incidence of poverty among other factors this study focuses on spatial variation across the united states in the retail costs for fresh vegetables and salty snacks findings reveal that the major economic and demographic characteristics of a household s community affect its costs for these two types of foods differently however households are likely to pay more money for salty snacks in communities where fresh vegetables also cost more

ramsey equilibrium in a two sector model with heterogeneous households abstract we prove an existence theorem for a stationary perfect foresight equilibrium under borrowing constraints in a two sector model with infinitely lived heterogeneous agents the most patient agent holds all the capital in this solution we also show that if the capital goods sector is capital intensive and capital income is increasing in the aggregate capital stock then the aggregate capital stock eventually is monotonic and converges to the steady state stock if the consumption goods sector is more capital intensive and capital income is increasing in aggregate capital we prove convergence to the steady state under more restrictive conditions periodic equilibria are shown to exist under weaker hypotheses journal of economic literature classification numbers d52 d90 e13

the role of capital depreciation in multi sectoral models abstract this study investigates the role of capital depreciation in economic fluctuations that may appear in multi sectoral models of optimal growth in the standard literature on non linear optimal dynamics it has been assumed that capital depreciates completely within a period this study in contrast deals with the case in which capital depreciates slowly more precisely only by a certain percentage we adopt the standard two sector model with cobb douglas production functions and characterize the dynamics around the stationary state we derive explicit conditions on parameter values under which cyclical optimal paths appear these conditions reveal the complexity that slow depreciation adds to multi sectoral optimal dynamics the economic interpretation of slow depreciation in multi sectoral models is also discussed

an empirical comparison of flexible demand system functional forms this paper compares the performance of eight frequently used flexible forms that are either 1 locally flexible 2 effectively globally regular or 3 asymptotically globally flexible results show that the functions with global properties generally perform better particularly those models having asymptotic properties results using us consumption data indicate substitutability among the components of consumption at most data points there is also some interesting substitution volatility around the time of recessions in the usa copyright 2001 john wiley sons ltd

demand systems with and without errors revealed preference theory assumes that each consumer has demands that are rational meaning that they arise from the maximization of his or her own utility function in contrast econometric or statistical demand models assume that each consumer s demands equal a rational systematic component derived from a common utility function plus an individual specific additive error term this paper reconciles these differences by providing necessary and sufficient conditions for rationality of statistical demand models given individual consumer rationality

agricultural productivity revisited this paper describes production accounts for agriculture output is defined as gross production leaving the farm as opposed to real value added inputs are not limited to capital and labor but include intermediate inputs as well we derive index numbers of gross output capital labor and intermediate inputs these data are used to construct indexes of total factor productivity we then compare the contributions of input growth and productivity growth to economic growth the important role of productivity growth in agriculture becomes immediately apparent

testing long run productivity models for the canadian and u s agricultural sectors the primary objective of this paper is to develop the linkages between the gross and net productivity indexes and the implied production structures these linkages are developed as separability restrictions on various subgroups of inputs and time in a general production model the restricted models are arranged in sequences for nested hypotheses testing empirical evidence from the u s and canadian agricultural sectors based on a translog production function support the gross output total factor productivity structure the net output hicks neutrality hypothesis is rejected for both the united states and canada

aggregation without separability composite commodity theorems in quantity space abstract in this paper we provide an obvious extension of the composite commodity theorems to the case of inverse demands where quantities and not prices can be used for aggregation first the hicks leontief commodity theorem is extended to the quantity space and then its generalised stochastic version is presented

perfectly competitive models of endogenous business fluctuations the endogenous hypothesis is not new at a pre analytic level it is based on the simple intuition that market mechanisms are inherently dynamically unstable at least around their stationary positions in this note i want to stress the theoretical point that there is nothing in the working of a perfectly competitive market system that prevents it from displaying persistent and endogenous fluctuations and that moreover such fluctuations may have their origins in market fundamentals such as factor intensities factor substitutability degree of impatience and so forth nevertheless macroeconomic models of endogenous fluctuations still have to prove that apart from being very beautiful they can also be useful to understand the so called heal world hit sunt leones this article is not intended to be a survey of all that has been written in this area in the last decade i have no title whatsoever to talk about empirical studies chera sayers contribution in this same volume addresses that guestion scheinkman 1990 is a readily available survey of nonlinear statistical methods that are relevant to this debate as for the theory incompetence recommends that i avoid touching on sunspot equilibria olg models and more generally expectations driven cycles they are instead discussed in jean michel grandmont s article finally marketing awareness implies recommending boldrin and woodford 1990 as a reasonably complete survey of what the endogenous cycle research program has recently produced at a theoretical level

non linear dynamics in the infinite time horizon model there are two important reasons why economic growth theory became again a popular field during the last 15 years the first one is that recently developed growth theoretic models capture more aspects of economic growth than the models used in the fifties and sixties nowadays models of economic growth try to explain technological progress and innovations whereas the purpose of traditional models was mainly to describe the process of capital accumulation

unobserved preference heterogeneity in demand using generalized random coefficients we model unobserved preference heterogeneity in demand systems via random barten scales in utility functions these barten scales appear as random coefficients multiplying prices in demand functions consumer demands are nonlinear in prices and may have unknown functional structure we therefore prove identification of generalized random coefficients models defined as nonparametric regressions where each regressor is multiplied by an unobserved random coefficient having an unknown distribution using canadian data we estimate energy demand functions with and without random coefficient barten scales we find that not accounting for this unobserved preference heterogeneity substantially biases estimated consumer surplus costs of an energy tax jel codes c14 d12 d13 c21 keywords unobserved heterogeneity nonseparable errors random utility parameters random coefficients equivalence scales consumer surplus welfare calculations the authors wish to thank jinyong hahn richard blundell stefan hoderlein rosa matzkin and anonymous referees for helpful discussions and suggestions earlier versions of this paper were circulated under the

latent separability grouping goods without weak separability this paper develops a new concept of separability with overlapping groups latent separability this is shown to provide a useful empirical and theoretical framework for investigating the grouping of goods and prices it is a generalization of weak separability in which goods are allowed to enter more than one group and where the composition of groups is identified by the choice of group specific exclusive goods latent separability is shown to be equivalent to weak separability in latent rather than purchased goods and provides a relationship between separability and household production theory for the popular class of linear almost ideal and translog demand models and their generalizations we provide a method for choosing the number of homothetic separable groups a detailed method for exploring the composition of the separable groups is also presented these methods are applied to a long time series of british individual household data on the consumption of twenty two nondurable and service goods

aggregation without separability a generalized composite commodity theorem this paper provides general conditions for aggregating commodities without separable utility these conditions impose weaker and more empirically plausible restrictions on price movements than the currently existing alternative to separability the hicks leontief composite commodity theorem the idea is to allow departures from hicks leontief that take the form of well behaved error terms utility functions that permit generalized composite commodity aggregation include the aids model the translog all homothetic utility functions and any utility function when demands are aggregated to two groups of goods implications of empirical nonstationarity of relative prices for aggregation and demand estimation are considered copyright 1996 by american economic association

trade liberalization and agricultural chemical use united states and mexico to anticipate the likely effects of recent trade agreements with mexico on the environment and food safety this paper examines changes in agricultural chemical use econometric estimation and simulation suggest that the combined effects of the north american free trade agreement nafta economic growth research investment and farm policy are expected to increase chemical usage substantially in the united states and undoubtedly lead to greater groundwater contamination in mexico the expected effects are a substantial increase in fertilizer use but a decrease in pesticide use increases in private research investment are expected to increase the use of both types of chemicals but increases in public research investment in the united states are not

a nonparametric analysis of the influence of research on agricultural productivity nonparametric productivity analysis is extended by modeling technical progress as a function of public and private research expenditures results indicate that 30 year lags are required to fully capture the effects of public research expenditures on u s agricultural productivity compared to public research private research has a stronger influence on farm productivity in the short term but a smaller influence in the longer term the internal rate of return is 0 28 for public research and 0 17 for private research

secrecy versus patenting we develop an equilibrium search model of innovation with the possibility of multiple independent discovery we distinguish innovations from ideas and we view patents as probabilistic property rights that are constrained by the innovators option to keep the innovation secret we find that the patent system can simultaneously stimulate innovation information disclosure and welfare an optimal patent may provide more or less protection than secrecy and in many cases it provides less suggesting that its main function is information spreading rather than rewarding the costs of the innovative activity

what percentage of innovations are patented empirical estimates for european firms abstract a 1993 survey on the innovative activities of europe s largest industrial firms obtained useable results on patenting activities for 604 respondents the data are used to calculate the sales weighted propensity rates for 19 industries the propensity rates equal the percentage of innovations for which a patent application is made the propensity rates for product innovations average 35 9 varying between 8 1 in textiles and 79 2 in pharmaceuticals the average for process innovations is 24 8 varying from 8 1 in textiles to 46 8 for precision instruments only four sectors have patent propensity rates for both product and process innovations combined that exceed 50 pharmaceuticals chemicals machinery and precision instruments regression results that control for the effect of industry sector show that patent propensity rates increase with firm size and are higher among firms that find patents to be an important method for preventing competitors from copying both product and process innovations the effect of secrecy is not so straightforward firms that find secrecy to be an important protection method for product innovations are less likely to patent as expected but secrecy has little effect on the propensity to patent process innovations the r d intensity of the firm has no effect on patent propensity rates for both product and process innovations the sector of activity has a strong influence on product patent propensities but very little effect on process patent propensities after controlling for the effect of other factors

on the minimum rate of impatience for complicated optimal growth paths the occurrence of complex dynamics in economic models has received wide attention by the economic profession during the last decade see boldrin and woodford 1990 for a recent survey one of the most interesting and surprising results obtained so far is the indeterminacy theorem of boldrin and montrucchio 1986b which implies that virtually every dynamical behavior is fully compatible with the standard assumptions of decreasing returns competitive markets and perfect foresight deneckere and pelikan 1986 have used a related approach to derive similar results for the special case of one dimensional dynamics whereas the analysis in boldrin and montrucchio 1986b and deneckere and pelikan 1986 is restricted to optimal growth models formulated in discrete time an analogous result holds also for the continuous time case see montrucchio 1988 and sorger 1990 all of these indeterminacy theorems have been proved by a constructive approach which requires a sufficiently high rate of impatience on the side of the decision maker in particular to construct optimal growth models exhibiting some well known chaotic maps like the logistic map or the henon map as optimal policy functions one needs time preference rates of more than 400

competitive equilibrium cycles recently there has been a surge of interest in endogenous business cycles that arise in competitive laissez faire economies in the context of standard overlapping generations economies conditions for the existence of equilibrium cycles have been given by grandmont 1983 and by benhabib and day 1982 models of the economy with extrinsic uncertainty or sunspots that have been developed by shell 1977 and by cass and shell 1983 see also balasko 1983 can also lead to equilibrium cycles

size distortions of tests of the null hypothesis of stationarity evidence and implications for the ppp debate abstract tests of the null hypothesis of stationarity against the unit root alternative play an increasingly important role in empirical work in macroeconomics and in international finance we show that the use of conventional asymptotic critical values for stationarity tests may cause extreme size distortions if the model under the null hypothesis is highly persistent this fact calls into question the use of these tests in empirical work we illustrate the practical importance of this point for tests of long run purchasing power parity ppp under the recent float we show that the common practice of viewing tests of stationarity as complementary to tests of the unit root null will tend to result in contradictions and in spurious rejections of long run ppp while the size distortions may be overcome by the use of finite sample critical values the resulting tests tend to have low power under economically plausible assumptions about the half life of deviations from ppp thus the fact that stationarity is not rejected cannot be interpreted as convincing evidence in favor of mean reversion only in the rare case that stationarity is rejected do size corrected tests shed light on the question of long run ppp

the dynamic responses of crop and livestock prices to money supply shocks a bayesian analysis using long run identifying restrictions the impact of monetary policy on agriculture has been much debated this study examines the dynamic responses of u s agricultural prices to money supply shocks using three innovations first the variables responses are identified by long run money neutrality restrictions instead of the more common contemporaneous ordering second a bayesian approach to model uncertainty is used to add robustness to the estimation process third agricultural prices are disaggregated into crop and livestock components the empirical results find that both agricultural sectors benefit in the short run from positive money supply shocks with agricultural prices increasing relative to the general price level

what happens to gazelles the importance of dynamic management strategy the starting point of this study is gibrat s law which is contrasted with strategic management this logic is subsequently applied to a group of remarkably dynamic high growth firms gazelles strategic management theory emphasises the importance of firms adjusting strategies in response to changes in the external environment in our study it is used to explain several key empirical findings using a novel british data set containing information on more than 100 gazelles these findings help explain 1 why gibrat s law of random firm growth processes does not generally hold 2 which strategy and environmental variables have a predictable influence on firm performance and 3 why routine application of best practice strategies is unlikely to foster firm growth in a changing economic environment in so doing this paper contributes to the large body of literature on small firm growth

indeterminacy and endogenous fluctuations in two sector growth models with externalities abstract this paper discusses the influence of technological externalities on the dynamic properties of accumulation paths in a two sector growth model in discrete time following the recent paper of boldrin and rustichini 1994 in which the authors study indeterminacy in a particular case we first provide some necessary and or sufficient conditions for the indeterminacy of equilibria in the general two sector model we also provide some conditions for the existence of period two cycles when equilibria are indeterminate we prove finally that depending on the nature of externality indeterminacy may lead to the existence of quasi periodic paths

motives to patent empirical evidence from germany abstract against the background of the patent upsurge we first analyse the role of patenting and alternative instruments to protect intellectual property based on a sample of german companies active in patenting in a second step we investigate the motives to patent considering sector and company size effects we find that company size matters both for the importance of instruments and the motives to patent especially important are the new strategic motives to patent like using patents to improve a company s own position in negotiations with partners licensees and the financial sector or to use patents as incentives for r d personnel or performance indicators these correlate positively with company size we derive some possible challenges for future patent policies from these insights

does patenting help high tech start ups abstract using data on all high and medium tech start ups in the uk in 2000 this paper assesses the effect associated with a firm s decision to patent on a firm s subsequent growth between 2001 and 2005 we propose a new approach to addressing well known issues challenging identification of any patent effect firm heterogeneity simultaneity between firm performance and patenting and sample selection our findings suggest that patentees have higher asset growth than non patentees of between 8 and 27 per annum 2011 elsevier b v all rights reserved

price formation of fish an application of an inverse demand system inverse demand systems explain price variations as functions of quantity variations they have properties analogous to those of regular demand systems there are very few examples of their empirical application in part this is due to lack of data for which price is the decision variable and the quantity given the case of fish landed at belgian sea ports appears to suit an inverse demand system well a rotterdam variant of such a system in estimated allais interaction intensities have been derived and show a reasonable pattern

the return to independent invention evidence of unrealistic optimism risk seeking or skewness loving examining a sample of 1 091 inventions i investigate the magnitude and distribution of the pre tax internal rate of return irr to inventive activity the average irr on a portfolio investment in these inventions is 11 4 this is higher than the risk free rate but lower than the long run return on high risk securities and the long run return on early stage venture capital funds the portfolio irr is significantly higher for some ex ante identifiable classes of inventions the distribution of return is skew only between 7 9 reach the market of the 75 inventions that did six realised returns above 1400 60 obtained negative returns and the median was negative

patents and patent policy a patent is the legal right of an inventor to exclude others from making or using a particular invention this right is sometimes termed an intellectual property right and is viewed as an incentive for innovation this article surveys the evidence on patent effectiveness in encouraging innovation and reviews the current controversies in patent policy

the sale of alcohol in denmark recent developments and dependencies on prices taxes how do prices affect the choice of types of alcohol in denmark we study the danish sale of alcoholic beverages in a time series framework first we look at annual data from 1980 investigating the hypothesis of a fairly stable level of sales we conclude stationarity of sales and we also find that the income elasticity of total sales has been zero second we analyse the composition of the alcohol sale between beer wine and spirits in a multivariate model conditional on the development in prices for this analysis we use johansen cointegration techniques again we test that income can be omitted from the model and we use the model to derive the effects on the composition of alcohol sales of three different sets of changes in the alcohol taxation

the effects of price aggregation bias in systems of demand equations this article illustrates the importance of maintaining consistent levels of aggregation between prices and quantities when estimating consumer demand functions the impact of violating this condition is quantified by using summary performance measures and estimates of demand elasticity biases results derived from an application of 1972 1973 consumer expenditure survey data and supported with a quasi monte carlo experiment consistently indicate that the point estimates of demand elasticities are significantly biased thus the study indicates the importance of developing and maintaining price indexes disaggregated to the same level as the expenditure data in consumer expenditure and budget surveys

the emergence of equilibrium cycles in a monetary economy with a separable utility function abstract this paper analyzes the dynamic properties of the monetary economy when money held during the period induces some utility it is shown that the price level and real money balances may have chaotic dynamic paths even if the utility function is separable in real money balances and consumption a crucial point is that a constraint on the utility of money yields the wealth effect that inflation will reduce the real value of assets hence as in the overlapping generations model the conflict between substitution and wealth effects may cause globally stable periodic orbits as well as the complicated dynamics

testing for homogeneity in demand systems when the regressors are nonstationary an implication of optimizing theory is that demand functions are homogeneous of degree zero in prices and nominal income evidence based on estimations of demand systems has repeatedly found this restriction to be rejected by the data however the hypothesis is often formulated in terms of regressors that are non stationary this paper re examines the evidence for homogeneity in light of recent developments in time series econometrics with special emphasis on the treatment of trends we find the demand system to be stochastically but not deterministically cointegrated using techniques developed for estimating cointegrating vectors in the presence of deterministic trends we re estimate the demand system and find that homogeneity holds in many cases

durable capital and chaos in competitive business cycles abstract this study constructs an example of chaotic optimal accumulation that results from the existence of the limitation of capital depreciation an example is an extension of the model developed by weitzman

wealth inequality and dynamic stability abstract we explore the link between wealth inequality and stability in a two sector neoclassical growth model with heterogeneous agents we show that when the inverse of absolute risk aversion or risk tolerance is a strictly convex function wealth inequality is a factor that favors instability in the opposite case inequality favors stability our characterization also shows that whenever absolute risk tolerance is linear as when preferences exhibit hyperbolic absolute risk aversion hara wealth heterogeneity is neutral

multiproduct supply and input demand in u s agriculture two sets of u s agricultural output supply and input demand relationships including cross price effects are reported for five commodity groups and four variable input groups for the 1951 82 period they are obtained by direct econometric estimation on u s data and by geographic aggregation from published econometric estimates for each of ten regions comprising the contiguous forty eight states the supply and demand formulations are specified on the assumptions of competitive behavior and an underlying normalized quadratic profit function the effects of upward sloping input supply curves are examined at the national level

aggregation of price risk over commodities an economic index number approach this article extends the economic theory of index numbers to the aggregation of price risk over commodities in production superlative indexes of aggregate price risk are related to tornqvist and fisher type output quantity indexes an application to major crops in manitoba illustrates the empirical importance of the analysis

estimates of the value of patent rights in european countries during the post 1950 period this paper examines the distribution of the values of patent rights in the united kingdom france and germany during the post 1950 period these values are inferred from the behavior of patentees with respect to payment of renewal fees on their patents a simple economic model of renewal decisions is combined with data on the proportion of patents renewed at alternative ages and the renewal fee schedules to produce estimates of the distribution and the total value of patent rights in these countries moreover the data indicate that there have been changes in the value distribution and we follow these changes over the period the empirical results of particular interest concern the total value of patent rights and the relationship between changes in it and changes in the quantity of patents the skew in the distribution of patent values and the rate of obsolescence on the returns to patents

competition between farmed and wild salmon the japanese salmon market this article examines the japanese market for salmon this market is of interest since it is the largest and most diversified salmon market in the world with wild and farmed species from europe and south and north america competing in the same market in contrast to the european union eu and u s markets there have been neither trade conflicts nor trade restrictions the japanese market can hence provide information about the impact of bringing substantial quantities of a new product into a market and the effect of large scale aquaculture on traditional fisheries in this article market integration between wild and farmed salmon on the japanese market is examined using both bivariate and multivariate cointegration analysis tests for the law of one price are also conducted the results indicate that the species are close substitutes on the market and that the expansion of farmed salmon has resulted in price decreases for all salmon species

estimating dynamic dual models under nonstatic expectations in this paper we derive a system of equations depicting agents dynamic decision rules under nonstatic price expectations based on the adjustment cost model of the firm the integrability conditions which can serve to guide the specification of flexible functional forms are established a two stage econometric model permitting empirical examination of both the expectations formation process and the dynamic structure of the industry is estimated using two different data series for u s production agriculture the estimation results suggest evidence of the presence of nonstatic price expectations in dynamic dual models for u s production agriculture

the generalized composite commodity theorem and food demand estimation this article reports tests of aggregation over consumer food products and estimates of aggregate food demand elasticities evidence that food demand variables follow unit root processes leads us to build on and simplify existing tests of the generalized composite commodity theorem we compute food demand elasticities using a method of cointegration that is shown to apply to a convenient but nonlinear functional form estimates are based on consumer reported expenditure data rather than commercial disappearance data appropriately specified models of consumer demand are central to market analysis it has been established that a valid equilibrium for markets characterized by diverse firms or diverse consumer products depends on downward sloping composite demand curves heiner braulke wohlgenant or on valid indirect utility functions chavas and cox given the large number of consumer food products food demand and price analysis must be implemented at some level of product aggregation improper aggregation can lead to biased estimates of welfare loss associated with public policies biased estimates of consumer and derived demand elasticities and misleading tests of market power testing for consistent aggregation over food products and estimating aggregate consumer food demand elasticities are the subjects of this article by far the most common justification for aggregation has been separable preferences one reason for its popularity has been the lack of a viable alternative tests of the composite commodity theorem hicks leontief lewbel are always rejected because it restricts relative prices within a group to remain fixed over time on the other hand aggregation based on weak separability is often rejected diewert and wales eales and unnevehr

hicksian separability does not hold over space implications for the design of household surveys and price questionnaires abstract if relative prices of goods within a commodity group are constant hicksian separability lets the price of a single good represent the group price level this is relied on by price questionnaires used with household surveys in developing countries and when constructing temporal and spatial deflators methods of estimating demand systems from household survey data also rely on hicksian separability yet this restriction remains untested in cross sections we use unique data from vietnam with multiple specifications from within the same food groups to test if within group relative prices are constant over space the data firmly reject these restrictions some guidelines for survey design are discussed in terms of the characteristics of commodity groups that should be disaggregated and those that should have more elementary goods added to their linked price questionnaire

nonparametric continuous discrete choice models modeling choices that are both discrete and continuous is important in several settings the purpose of this article is to explore formulation and identification of such models when indirect utility functions are specified nonparametrically here we consider general nonseparable disturbances we give identification results for nonseparable sample selection models and use these to analyze identification of discrete continuous choice models

sources of complex dynamics in two sector growth models this paper develops a tractable multisectoral dynamic equilibrium model and provides a fairly complete analysis of the dynamics that may arise along the intertemporal competitive equilibrium path despite the fact that the environment displays neither random nor deterministic variability the model may produce oscillations in aggregate variables such as output consumption and investment we show that these oscillations can be exactly periodic of any finite period i and even totally aperiodic chaotic we characterize the parameter values for which each of these cases occur but also provide some strong global asymptotic stability results

resource rent in individual quota fisheries traditional fisheries management schemes generate incentives for vessels to maximize catch resulting in rent dissipation and overcapacity individual vessel quota management schemes change the incentives to maximize profit and have the potential to generate resource rent and reduce capacity an interesting question is whether it is the changed incentives due to individual quota or the capacity reduction due to transferability of individual quota that is most important in generating rent in this study a cost function approach is used to model and measure rent generated and potential rent in a fishery managed with individual vessel quotas

agricultural trade restrictiveness in the european union and the united states the article provides a summary measure of the uruguay round tariff reduction commitments in the european union and the united states using the mercantilistic trade restrictiveness index mtri as the tariff aggregator we compute the index for agricultural commodity aggregates assuming a specific constant elasticity of substitution functional form for import demand the levels of the mtri under the actual commitments of the uruguay round are computed and compared with two hypothetical cases a deeper cut in higher tariffs and a uniform reduction of each tariff both leading to the same average reduction as in the uruguay round this makes it possible to infer how reducing tariff dispersion will help improve market access in future trade agreements and provides some guidelines for aggregating detailed tariffs in trade models

the heckman correction for sample selection and its critique this paper gives a short overview of monte carlo studies on the usefulness of heckman s 1976 1979 two step estimator for estimating selection models such models occur frequently in empirical work especially in microeconometrics when estimating wage equations or consumer expenditures it is shown that exploratory work to check for collinearity problems is strongly recommended before deciding on which estimator to apply in the absence of collinearity problems the full information maximum likelihood estimator is preferable to the limited information two step method of heckman although the latter also gives reasonable results if however collinearity problems prevail subsample ols or the two part model is the most robust amongst the simple to calculate estimators

endogenous price fluctuations in an optimizing model of a monetary economy this paper demonstrates that an optimizing model of a monetary economy can produce perfect foresight equilibria in which the price level fluctuates forever cyclically or chaotically fluctuating equilibria are more likely to exist when the rate of money supply growth is high furthermore the set of equilibrium prices may have a complicated topological structure which poses a more serious problem concerning the validity of comparative statics method than any sort of indeterminacy previously discussed in the literature copyright 1991 by the econometric society

the output bias of technological change in postwar japanese agriculture in order to explain the rapid change in the output mix this study tests the hypothesis that technological change in postwar japanese agriculture was biased towards livestock production a multioutput translog cost function was estimated for the 1958 84 period in which results are consistent with the hypothesis furthermore changes in the composition of crop and livestock production had significant impacts on relative factor uses above all expanding livestock production required relatively less labor than expanding crop production implying a positive contribution to the rapid exodus of labor to the nonagricultural sectors

aggregation of data and profit maximization in mexican agriculture nonparametric support for two important hypotheses relevant to econometric model specification is examined results of various nonparametric tests for behavioural objective and aggregation level of mexican agricultural production data are reported the evidence does not refute the hypothesis that producers behave collectively as though they are a price taking profit maximizing firm the empirical results also support exhaustive aggregation of input categories aggregation possibilities among outputs are fewer and are highly sensitive to the rejection criterion