evolution of the economics of agricultural policy agricultural economists helped develop farm programs to respond to the dire economic situation of the 1920s and 1930s some early authors appreciated that such policies created problems in markets for commodities and inputs over time our understanding of agricultural issues and policies has deepened through the application of improved models and tools of analysis to more extensive data we have developed better answers to old questions and have responded to changing policy instruments market contexts and policy concerns this article traces the evolution of our deepening economic understanding of the causes and consequences of agricultural policy

political economic markets perts and pests in food and agriculture j i lyniversity of california berkeley jjept of agricultural and resource economic l working paper al cljdare i lorking paper 0 231 politic eco lic l rxets a d pests i j food l ti achiculture by per ts cordon c rausser ja nlnl tt junot tlon a riii ent st ticn giannini fou 1cl itiol1of ar ricultllrnj econo ll i cs july 11 w

on the political economy of public good inputs in agriculture the paper analyzes two elements in explaining and prescribing the level of costreducing public good inputs in agriculture the distribution of political influence and the economic properties of markets the incidence of costs benefits of alternative costsharing arrangements between taxpayers and producers is compared to the social optimal and competitive outcomes although one group could lose we focus only on situations of a pareto improvement the model predicts why some sectors have relatively more public versus private research funding and why the degree of underinvestment varies across sectors the observed underinvestment in agriculture may be due to the political power of farmers inelastic demand and highly productive public good inputs

international portfolio choice and political instability risk a multi objective approach abstract the benefits derived from international portfolio diversification into foreign nations including the less developed countries are well documented yet this practice is discouraged due to market imperfections such as political instability in practice nations may be differentiated further by many aspects such as border controls or political and social trends which constrain private transactions and financial decisions this paper attempts to examine 1 whether the home asset bias in a portfolio holding is associated with higher political instability risk and 2 to what extent international diversification among stocks in the presence of such risk outperforms domestic stock portfolios using alternative instability risk proxies in the context of a discrete time version of mean variance framework we corroborate the impact of this type of risk on international portfolio investment decisions

influencing the influencers a theory of strategic diffusion the growth of the internet and assorted technologies has made it possible to collect and process detailed information on social networks this article investigates how firms and governments can harness the power of social networks to promote their goals we show that the optimal use of social networks leads to higher sales and greater profits however an increase in the level and dispersion of social interaction can increase or decrease the optimal influence strategy and profits of the player depending on the content of the interaction optimal influence strategies will target individuals with low or high connections depending on the content of interaction finally the returns to investing in market research on social networks are greater in more unequal networks

advertising learning and consumer choice in experience good markets an empirical examination this article empirically analyzes different effects of advertising in a nondurable experience good market a dynamic learning model of consumer behavior is presented in which i allow both informative effects of advertising and prestige or image effects of advertising this learning model is estimated using consumer level panel data tracking grocery purchases and advertising exposures over time empirical results suggest that in this market advertising s primary effect was that of informing consumers the estimates are used to quantify the value of this information to consumers and evaluate the welfare implications of an alternative advertising regulatory regime

customer referral incentives and social media we study how to optimally attract new customers using a referral program whenever a consumer makes a purchase the firm gives her a link to share with friends and every purchase coming through that link generates a referral payment the firm chooses the referral payment function and consumers play an equilibrium in response the optimal payment function is nonlinear and not necessarily monotonic in the number of successful referrals if we approximate the optimal policy using a linear payment function the approximation loss scales with the square root of the average consumer degree using a threshold payment the approximation loss scales proportionally to the average consumer degree combining the two using a linear payment function with a threshold bonus we can achieve a constant bound on the approximation loss this paper was accepted by noah gans stochastic models and simulation

innovation policy in an open economy a normative framework for strategic and tactical issues abstract in this paper we present a normative analysis of innovation policy grounded in traditional economic principles which responds to the schumpeterian critique of previous efforts in the neoclassical vein focusing directly on specific policy issues we pursue our analysis in two main directions investigating the role of government in developing an infrastructure for innovation and the optimal design of support schemes for r d projects the analysis suggests that while the structural and developmental issues stressed by the schumpeterian school are of fundamental importance identification of disparities between social and private gains the market failure approach provides an invaluable tool for understanding and formulating innovation policy focusing our attention on such factors as economics of scale the incidence of externalities and the supranormal profits offered by imperfectly competitive markets it provides a rational and realistic basis for anticipating where and how government intervention on behalf of industrial innovation is likely to be most effective we view our contribution as a step towards bridging the gap between the neoclassical mainstream of economic analysis and the practice of innovation policy

word of mouth communication and percolation in social networks this paper develops a model of demand pricing and advertising in the presence of social learning via word of mouth communication between friends in the model consumers must receive information about a monopolist s product in order to consider purchasing it the presence of word of mouth is not sufficient for demand to be more elastic and prices to be lower compared to an informed population i derive the comparative static results of connectivity mean preserving spread of friendships and clustering of friends on prices the optimal targets for advertising are not generically the individuals with the most friends jel l12 l14 a fundamental issue for economists is understanding the process by which demand is formed through social learning by consumers this article develops a framework based on random graphs for understanding the ways social learning via

an economic analysis of expenditures on agricultural experiment station research experiment station research expenditures are responsive to economic and institutional forces a four equation model of resources allocation to state agricultural experiment station research consisting of demand and supply equations for research an equation allocating state governmental revenues to station research and an expenditure identity is presented a reduced form expenditure equation derived from this model is fitted to cross sectional data for forty eight u s states pooled together for 1960 1965 and 1970 a large share of the variance in per capita expenditures of state agricultural experiment stations is explained by the variables included in the model

unobservable industry characteristics and the innovation concentration advertising maze evidence from an econometric study using panel data for manufacturing industries in the frg 1979 1986 in discussing the nexus between innovations and market structure it is often argued that industry characteristics called opportunities might play an important role as determinants of innovation and that simultaneity rather than one way causality prevails we consider a three equation model for innovation advertising and concentration based on pooled cross section time series data for 26 german manufacturing industries we estimate single equation models with and without fixed industry and or time effects to control for unobservable industry or time effects respectively and simultaneous equation systems including fixed effects and controlling for extreme cases outliers or not furthermore we use two different measures for innovations i e the percentage of shipments due to new products and the percentage of firms which classified themselves as innovators our results can be summarized as follows 1 the firm size has no significant effect on innovation one can therefore not conclude from this data set that large firms are more innovative than small ones 2 unobservable industry effects do matter 3 the treatment of outliers does matter 4 simultaneity does matter 5 the way innovations are measured does matter 6 different stories could be told based on the results of the systems of interdependent equations estimated

a new product growth for model consumer durables this article originally appeared in management science january 1969 volume 15 number 5 pp 215 227 published by the institute of management sciences a growth model for the timing of initial purchase of new products is developed and tested empirically against data for eleven consumer durables the basic assumption of the model is that the timing of a consumer s initial purchase is related to the number of previous buyers a behavioral rationale for the model is offered in terms of innovative and imitative behavior the model yields good predictions of the sales peak and the timing of the peak when applied to historical data a long range forecast is developed for the sales of color television sets

decision making under uncertainty capturing dynamic brand choice processes in turbulent consumer goods markets we construct two models of the behavior of consumers in an environment where there is uncertainty about brand attributes in our models both usage experience and advertising exposure give consumers noisy signals about brand attributes consumers use these signals to update their expectations of brand attributes in a bayesian manner the two models are 1 a dynamic model with immediate utility maximization and 2 a dynamic forward looking model in which consumers maximize the expected present value of utility over a planning horizon given this theoretical framework we derive from the bayesian learning framework how brand choice probabilities depend on past usage experience and advertising exposures we then form likelihood functions for the models and estimate them on nielsen scanner data for detergent we find that the functional forms for experience and advertising effects that we derive from the bayesian learning framework fit the data very well relative to flexible ad hoc functional forms such as exponential smoothing and also perform better at out of sample prediction another finding is that in the context of consumer learning of product attributes although the forward looking model fits the data statistically better at conventional significance levels both models produce similar parameter estimates and policy implications our estimates indicate that consumers are risk averse with respect to variation in brand attributes which discourages them from buying unfamiliar brands using the estimated behavioral models we perform various scenario evaluations to find how changes in marketing strategy affect brand choice both in the short and long run a key finding obtained from the policy experiments is that advertising intensity has only weak short run effects but a strong cumulative effect in the long run the substantive content of the paper is potentially of interest to academics in marketing economics and decision sciences as well as product managers marketing research managers and analysts interested in studying the effectiveness of marketing mix strategies our paper will be of particular interest to those interested in the long run effects of advertising note that our estimation strategy requires us to specify explicit behavioral models of consumer choice behavior derive the implied relationships among choice probabilities past purchases and marketing mix variables and then estimate the behavioral parameters of each model such an estimation strategy is referred to as structural estimation and econometric models that are based explicitly on the consumer s maximization problem and whose parameters are parameters of the consumers utility functions or of their constraints are referred to as structural models a key benefit of the structural approach is its potential usefulness for policy evaluation the parameters of structural models are invariant to policy that is they do not change due to a change in the policy in contrast the parameters of reduced form brand choice models are in general functions of marketing strategy variables e g consumer response to price may depend on pricing policy as a result the predictions of reduced form models for the outcomes of policy experiments may be unreliable because in making the prediction one must assume that the model parameters are unaffected by the policy change since the agents in our models choose among many alternative brands their choice probabilities take the form of higher order integrals we employ monte carlo methods to approximate these integrals and estimate our models using simulated maximum likelihood estimation of the dynamic forward looking model also requires that a dynamic programming problem be solved in order to form the likelihood function for this we use a new approximation method based on simulation and interpolation techniques these estimation techniques may be of interest to researchers and policy makers in many fields where dynamic choice among discrete alternatives is important such as marketing decision sciences labor and health economics and industrial organization

cellular telephone new products and the cpi since their introduction in 1983 cellular telephones adoption has grown at 25 35 per year at year end 1997 about 55 million cellular telephones were in use in the united states the bureau of labor statistics bls did not know that cellular telephones existed at least in terms of calculating the consumer price index cpi until 1998 when they were finally included in the cpi omitting cellular telephones from the cpi created a significant bias i estimate a bias in the bls estimate of the telecommunications services index of between 8 1 9 per year because of the omission of the cellular telephone rather than telecommunications service prices increasing at about 1 1 per year the correct calculation has them decreasing at about 8 per year omission of new goods from the cpi for significant periods of time leads to important bias in the calculation of the cpi

monopoly pricing and diffusion of social network goods abstract i present a model of dynamic pricing and diffusion of a network good sold by a monopolist in the model the network good is a subscription social network good this means that in each period each consumer has to pay a subscription price to use the good and the utility derived from subscribing to the good increases as more of her neighboring consumers subscribe consumers myopically optimize their subscription decisions and the monopolist chooses a sequence of subscription prices that maximizes his discounted sum of per period profits three main results emerge first i characterize a unique steady state of the monopoly market second i find that optimal sequences of subscription prices oscillate around the subscription price at the steady state third i analyze how changes in the monopolist s discount factor and the density of the social network affect the subscription price subscription rate and deadweight loss at the steady state

meeting strangers and friends of friends how random are social networks we present a dynamic model of network formation where nodes find other nodes with whom to form links in two ways some are found uniformly at random while others are found by searching locally through the current structure of the network e g meeting friends of friends this combination of meeting processes results in a spectrum of features exhibited by large social networks including the presence of more high and low degree nodes than when links are formed independently at random having low distances between nodes in the network and having high clustering of links on a local level we fit the model to data from six networks and impute the relative ratio of random to network based meetings in link formation which turns out to vary dramatically across applications we show that as the random network based meeting ratio varies the resulting degree distributions can be ordered in the sense of stochastic dominance which allows us to infer how the formation process affects average utility in the network

consumer search with observational learning this article studies observational learning in a consumer search environment consumers observe the purchasing decision of a predecessor with similar preferences consumers rationally emulate by initiating their search at the firm from which their predecessor purchased free riding on search effort and reacting less to price changes prices are nonmonotone in search costs and may be as low as marginal costs we discuss several extensions and show that the effect of emulation on prices is stronger when i the number of firms increases ii consumers first visits are more elastic with respect to market shares and iii prices are adjusted more frequently

foreign ownership and technology adoption evidence from indian firms abstract firms in developing countries rely on foreign technology purchases to improve their technology we use a theoretical framework developed by katz and shapiro to examine the ongoing technology adoption behavior of foreign owned and domestic firms using firm level data on indian firms from 1989 to 1993 we test this theoretical model we find that foreign ownership firm size and market structure are among the variables that impact a firm s probability of adopting new technology we also find that the 1991 liberalization of technology transfer policies in india appears to have had a larger impact on foreign owned firms than domestic firms

conversations among competitors conversation is a central part of economic life a wide range of information gets passed from one person to another via word of mouth communication and a number of authors argue that the nature of connections between people i e the structure of social networks can have a

an evaluation of federal policy instruments to stimulate basic research in industry a model of the resource allocation behavior of a group of firms demonstrates that unaided industry allocation to basic inappropriable research is suboptimal furthermore provision of seed money is generally counterproductive while the provision of a matching subsidy is not very cost efficient in increasing the allocation innovative policy alternatives are proposed

diffusion of behavior and equilibrium properties in network games situations in which agents choices depend on choices of those in close proximity be it social or geographic are ubiquitous selecting a new computer platform signing a political petition or even catching the flu are examples in which social interactions have a significant role while some behaviors or states propagate and explode within the population e g windows os the hiv virus others do not e g certain computer viruses our goal in this paper is twofold first we provide a general dynamic model in which agents choices depend on the underlying social network of connections second we show the usefulness of the model in determining when a given behavior expands within a population or disappears as a function of the environment s fundamentals we study a framework in which agents face a choice between two actions 0 and 1 e g whether to pursue a certain level of education switch to linux os etc agents are linked through a social network and an agent s payoffs from each action depend on the number of neighbors she has and her neighbors choices the diffusion process is defined so that at each period each agent best responds to the actions taken by her neighbors in the previous period assuming that her neighbors follow the population distribution of actions a mean field approximation steady states correspond to equilibria of the static game under some simple conditions equilibria take one of two forms some are stable so that a slight perturbation to any such equilibrium would lead the diffusion process to converge back to that equilibrium point other equilibria are unstable so that a slight change in the distribution of actions leads to a new distribution of actions and eventually to a stable steady state we call such equilibria tipping points we analyze how the environment s fundamentals cost distribution payoffs and network structure affect the set of equilibria and characterize the adoption patterns within the network the paper relates to recent work on network games and network diffusion including work by stephen morris 2000 pastor satorras and vespignani 2000 mark e j newman 2002 dunia lopez pintado 2004 jackson and brian w rogers 2007 jackson and yariv 2005 and andrea galeotti et al 2005 henceforth ggjvy its contribution is in characterizing diffusion of strategic behavior and analyzing the stability properties of equilibria and employing methods that allow us to make comparisons across general network structures and settings given that social networks differ substantially and systematically in structure across settings e g ethnic groups professions etc understanding the implications of social structure on diffusion is an important undertaking for a diverse set of applications

buyer market structure and r d effort a simultaneous equations model the theoretical and empirical investigations of the relationship between market structure and the firm s incentive to invent and innovate have concentrated on the effects of the structure of the supply side of the market this focus on the supply side originated in schumpeter s controversial hypothesis that current market power provided the necessary conditions and future market power provided the incentive for technical change schumpeter 1950 this hypothesis stimulated a vast number of theoretical refinements and empirical tests of relations between research and development activity r d and supply side characteristics such as concentration firm size and diversification this literature has been well summarized by kamien and schwartz 1975 and scherer 1980 the analysis of the effects of the buyer market structure on the selling industry conduct and performance has been limited both theoretically and empirically stigler 1964 modeled the effects of the size distribution of buyers on price competition in oligopoly telser 1964 devel oped a theory of advertising messages in which he suggested that advertising would increase when buyers were many and small lustgarten 1975 tested the effects of buyer market structure on price cost margins and advertising and found the relations suggested by stigler and telser invention and innovation are forms of competition which like price and advertising will be affected by both buyer market structure and seller market structure however unlike price and advertising competition there have not been explicit attempts to establish theoretical and empirical relations between buyer market structure and inventive and innovative activity the effects of buyer market structure on the selling industry s incentive to invent and innovate is relevant to interpreting the effects of seller market structure on this effort a number of previous studies of the effects of seller market structure on technical change have found that seller concentration may have a slight positive impact on inventive and innovative effort kamien and schwartz 1975 p 20 even this weak relation may be due to not controlling for buyer market structure if galbraith s 1952 countervailing power hypothesis is correct lustgarten 1975 p 128 concentration in the buyer and seller markets may be positively correlated if buyer market concentration is positively related to inventive and innovative effort in the selling industry the empirical estimate of the partial effect of seller concentration will be biased upward this paper investigates the effect of buyer market structure on r d effort section ii draws together the literature that is relevant to the issue of the relation between buyer market structure and seller inventive and innovative activity section iii develops a simultaneous equation model of r d activity where r d advertising and concentration are endogenous variables section iv uses data on scientific and engineering inputs to test this model section v summarizes these results

pricing network effects the increase in the information that firms can collect or purchase about network effects across consumers motivates two important questions how does a firm s pricing strategy react to detailed information on network effects are the availability and use of such information beneficial or detrimental to consumer surplus we develop a model in which a monopoly sells a network good and price discriminates based on information about consumers influence and consumers susceptibility to influence the monopoly optimally offers consumers price discounts for their influence and charges price premia for their susceptibility the price premia and the price discounts are simple functions of the pattern of network effects we determine under which conditions relative to uniform price consumer surplus increases and we characterize the value of information on network effects for the monopoly

north south the implications for multinational banking abstract international finance should be of great value to developing countries because their potential growth paths are out of step with the world economy and because the gambles they must take to develop are much more diversifiable in the context of the world economy than locally however the actual benefits of north south finance have been limited by an overreliance on non specific bank credit with the inherent limitations and by errors in judgement by both borrowers and lenders in fact the current crisis threatens to reverse many of the earlier gains while the current crisis is primarily the result of the world recession the severity of its effects on lenders and borrowers reflects three key aspects of bank credits 1 its perverse real repayment patterns 2 its specific nature which implies that risks are transferred only through generalized non performance with its attendant deadweight costs and 3 its concentration in a small but critical segment of capital markets these characteristics would be serious even with ideal behavior by lenders and borrowers but they also can lend to inappropriate and possibly erratic behavior specific suggestion for restructuring the system of north south finance are given including 1 smoothing repayment patterns 2 increasing repayment flexibility 3 increasing risk bearing non specific finance 4 increasing non recourse financing and 5 increasing project specific risk capital

schumpeterian dynamics an evolutionary model of innovation and imitation abstract this paper develops a simple evolutionary model of innovation and imitation it analyzes how dynamic interactions between equilibrating force of imitation and disequilibrating force of innovation mold the evolutionary pattern of an industry s state of technology and shows that in this schumpeterian world the industry will never approach a neoclassical equilibrium with perfect knowlwdge even in the long run the paper also examines the steady state efficiency distribution of firms that characterizes the industry s long run and obtains some comparative dynamics results

filtered social learning knowledge sharing is economically important but also typically incomplete we filter our communication this paper analyzes the consequences of filtering in the model homogeneous agents share knowledge with their peers whenever the private benefits exceed communication costs the welfare implications of this transmission mechanism hinge on whether units of knowledge complement substitute for or are independent of each other both substitutability and complementarity generate externalities cheaper communication eliminates externalities in the former case but not necessarily in the latter complementary basic skills such as numeracy catalyze technology adoption and adoption may be path dependent even when payoffs are certain and independent across agents

the political economy of public research investment and commodity policies in agriculture an empirical study the paper tests a political economy theory of simultaneous government decision making on income redistribution through commodity policies and on public research investment in agriculture we use data from 37 countries on agricultural protection and public agricultural research expenditures pari the empirical results are consistent with the political economy hypotheses the analysis suggest that structural changes in the economy have important effects on the political incentives for governments not only to subsidize or tax farmers but also to invest in public agricultural research furthermore the analysis supports the hypotheses that the impact of such structural changes on government decision making on pari is non linear and conditional on other factors regarding the impact of political institutions the results suggest that more democracy neither leads to more distortionary transfers agricultural protection nor to lower investment in public goods pari

noisy contagion without mutation in a local interaction game agents play an identical stage game against their neighbours over time for nearest neighbour interaction it is established that starting from a random initial configuration in which each agent has a positive probability of playing the risk dominant strategy a sufficiently large population coordinates in the long run on the risk dominant equilibrium almost surely our result improves on blume 1995 ellison 2000 and morris 2000 by showing that the risk dominant equilibrium spreads to the entire population in a two dimensional lattice and without the help of mutation as long as there is some randomness in the initial configuration

stability analysis of financial contagion due to overlapping portfolios abstract common asset holdings are widely believed to have been the primary vector of contagion in the recent financial crisis we develop a network approach to the amplification of financial contagion due to the combination of overlapping portfolios and leverage and we show how it can be understood in terms of a generalized branching process this can be used to compute the stability for any particular configuration of portfolios by studying a stylized model we estimate the circumstances under which systemic instabilities are likely to occur as a function of parameters such as leverage market crowding diversification and market impact although diversification may be good for individual institutions it can create dangerous systemic effects and as a result financial contagion gets worse with too much diversification there is a critical threshold for leverage below it financial networks are always stable and above it the unstable region grows as leverage increases note that our model assumes passive portfolio management during a crisis however we show that dynamic deleveraging during a crisis can amplify instabilities the financial system exhibits robust yet fragile behavior with regions of the parameter space where contagion is rare but catastrophic whenever it occurs our model and methods of analysis can be calibrated to real data and provide simple yet powerful tools for macroprudential stress testing

innovation diffusion in heterogeneous populations contagion social influence and social learning new ideas products and practices take time to diffuse a fact that is often attributed to some form of heterogeneity among potential adopters this paper examines three broad classes of diffusion models contagion social influence and social learning and shows how to incorporate heterogeneity into each at a high level of generality without losing analytical tractability each type of model leaves a characteristic footprint on the shape of the adoption curve which provides a basis for discriminating empirically between them the approach is illustrated using the classic study of ryan and gross 1943 on the diffusion of hybrid corn

returns to acquirers of privatizing financial services firms an international examination abstract while the literature reports improved performance for privatizing firms banking markets are different many privatizing financial services firms face unique problems such as an overhang of problem loans and weak credit cultures and legal systems we investigate the returns to successful bidders in privatization acquisitions of financial services firms examine short horizon performance and test whether such acquisitions result in a change in risk for the bidding firm our results show that the cumulative abnormal returns to shareholders of bidding firms are positive perhaps reflecting initial optimism that the foreign firm acquiring the privatizing firm would share in the success associated with privatization bidders also experience an increase in their total risk following the acquisition

generics and new goods in pharmaceutical price indexes drug prices and their rate of inflation are a major focus of current policy debates on u s health care in this paper we show that where patent expiration and generic entry are significant as they are for many important classes of drugs movements in the official price indexes may be poor indicators of the actual prices paid and the resulting changes in consumer welfare when a drug goes off patent those consumers who regard the branded and generic versions as more or less perfect substitutes experience a substantial price decline and concomitant welfare gain which the current methods used by the statistical agencies fail to capture we suggest a number of alternative ways of proceeding although our computations are based on a limited number of cases they imply that the overall rate of inflation in drug prices may be quite seriously overstated while generic pharmaceuticals are the topic of our calculations the problem discussed is also of wider importance generic drugs are a special and possibly easy case

international comparisons of r d effort the case of the canadian pharmaceutical industry abstract the canadian federal government anxious to stimulate innovation announced recently a policy objective for the economy the attainment of industrial research expenditures reaching 1 5 percent of the gross national product the proposed substantial increase over the current level is rationalized by comparison with economy wide research intensities gerd gnp in other oecd countries this paper questions the economic validity and policy relevance of international aggregate comparisons it argues that inter country comparisons should take place at individual industry levels where technologies are similar and proposes a methodology for formulating rd this canadian industry presumably does not require governmental attention to its r d activities

monopoly pricing in the presence of social learning a monopolist offers a product to a market of consumers with heterogeneous quality preferences although initially uninformed about the product quality they learn by observing past purchase decisions and reviews of other consumers our goal is to analyze the social learning mechanism and its effect on the seller s pricing decision consumers follow an intuitive non bayesian decision rule under conditions that we identify we show that consumers eventually learn the product s quality we show how the learning trajectory can be approximated in settings with high demand intensity via a mean field approximation that highlights the dynamics of this learning process its dependence on the price and the market heterogeneity with respect to quality preferences two pricing policies are studied a static price and one with a single price change finally numerical experiments suggest that pricing policies that account for social learning may increase revenues considerably relative to policies that do not this

market structure innovation and optimal patent life m uch work has been directed at determining the relative efficiency of various market structures in the allocation of resources to invention while the conclusions are not entirely clear it seems certain that no single market structure results in a pareto efficient allocation of resources to research and development r d in the light of this certain secondbest procedures must be examined social controls may provide an attractive method of lessening the inefficiencies described above 2 while government research and development subsidies and award programs do exist the most prevalent form of social control is the patent system granting the inventor a monopoly on the use of the discovery for a specified period of time eliminates the free rider problem thus restoring the incentive to invent extension of the duration of protection will increase incentives for private resource allocation toward technical advance unfortunately extension of patent protection by definition brings with it the social inefficiencies recognized in a monopolistic market the

market structure and innovation a survey economics we all recite deals with allocation of limited resources towards satisfaction of unlimited wants resources are typically identified as land labor and capital plus a technology that determines their transformation into consumer goods disparity between the available goods and services and the desired gives rise to scarcity and the question of what how and for whom to produce the focus then shifts to description and evaluation of alternative resource allocation mechanisms for making the choices the pareto criterion by which an allocation of resources is deemed efficient if any reallocation improving the position of some individual worsens the position of others is a commonly employed gauge of a mechanism s performance in the absence of externalities increasing returns to scale and uncertainty a perfectly competitive market system yields a pareto optimal allocation of resources this underlies the view that individual self interest is compatible with society s interest the further conclusion that pareto optimality may not be achieved via the market system in the presence of monopoly elements provides an economic rationale for antitrust laws the objective of a resource allocation mechanism appears to be according to the analysis described above to make the best of available resources the alternative objective of relaxing constraints through expanding the resource base or developing new technology seems to be beyond its scope thus until rather recently technical advance had been regarded in the mainstream of economic theory as unmotivated by the quest for profits and substantially unaffected by resource allocation instead as j schmookler observed technology had been viewed as a parameter like the weather affecting the outcome of resource allocations but itself unaffected by them 84 1965 evidence that technological progress has significantly contributed to growth in productivity together with a substantial increase in research and development activity largely financed by government and carried out by industry see f machlup 51 1962 may have spurred reconsideration of this view once technical advance is regarded as an economic variable it is natural to in

strategic commitment with r d the case of bertrand competition abstract when there is multiplicatively separable demand and firms compete in the price dimension there is no room for strategic use of r d by firms under a different demand situation strategic use of r d by firms competing in the price dimension reduces r d spending reduces output increases price and increases profits of each firm

pricing and referrals in diffusion on networks abstract when a new product or technology is introduced potential consumers can learn its quality by trying it at a risk or by letting others try it and free riding on the information that they generate we propose a dynamic game to study the adoption of technologies of uncertain value when agents are connected by a network and a monopolist seller chooses a profit maximizing policy consumers with low degree few friends have incentives to adopt early while consumers with high degree have incentives to free ride the seller can induce high degree consumers to adopt early by offering referral incentives rewards to early adopters whose friends buy in the second period referral incentives thus lead to a double threshold strategy by which low and high degree agents adopt the product early while middle degree agents wait we show that referral incentives are optimal on certain networks while inter temporal price discrimination is optimal on others

investment in developed and less developed countries a number of studies have compared the investment risk of various industries and of various individual corporations in developed countries dcs the purpose of this paper is to compare investment risk in dcs with less developed countries ldcs the variance of returns to investment in common stocks provides a natural measure of investment risk and will be used in this study studies in ldcs include work of levy and sarnat 12 13 errunza 3 4 and lessard 11 levy and sarnat and errunza found low economy wide investment risk on an average for ldcs relative to dcs with stock indices being used as surrogates for economy wide risk these results are not unambiguous however because there are probable difficulties due to infrequent trading and averaging in the broad market indices used in the above studies hence we use a sample of the largest corporations that suffer little if at all from thin trading and or averaging

new product diffusion with influentials and imitators we model the diffusion of innovations in markets with two segments influentials who are more in touch with new developments and who affect another segment of imitators whose own adoptions do not affect the influentials this two segment structure with asymmetric influence is consistent with several theories in sociology and diffusion research as well as many viral or network marketing strategies we have four main results 1 diffusion in a mixture of influentials and imitators can exhibit a dip or chasm between the early and later parts of the diffusion curve 2 the proportion of adoptions stemming from influentials need not decrease monotonically but may first decrease and then increase 3 erroneously specifying a mixed influence model to a mixture process where influentials act independently from each other can generate systematic changes in the parameter values reported in earlier research 4 empirical analysis of 33 different data series indicates that the two segment model fits better than the standard mixed influence the gamma shifted gompertz and the weibull gamma models especially in cases where a two segment structure is likely to exist also the two segment model fits about as well as the karmeshu goswami mixed influence model in which the coefficients of innovation and imitation vary across potential adopters in a continuous fashion

dynamics of consumer demand for new durable goods most new consumer durable goods experience rapid prices declines and quality improvements suggesting the importance of modeling dynamics this paper specifies a dynamic model of consumer preferences for new durable goods with persistently heterogeneous consumer tastes rational expectations and repeat purchases over time we estimate the model on the digital camcorder industry using panel data on prices sales and characteristics we find that the 1 year elasticity in response to a transitory industrywide price shock is about 25 percent less than the 1 month elasticity standard cost of living indices overstate welfare gain in later periods due to a changing composition of buyers

consumption risk sharing in social networks we develop a model of informal risk sharing in social networks where relationships between individuals can be used as social collateral to enforce insurance payments we characterize incentive compatible risk sharing arrangements and obtain two results 1 the degree of informal insurance is governed by the expansiveness of the network measured by the number of connections that groups of agents have with the rest of the community relative to group size twodimensional networks where people have connections in multiple directions are su ciently expansive to allow very good risk sharing we show that social networks in peruvian villages satisfy this dimensionality property thus our model can explain townsend s 1994 puzzling observation that village communities often exhibit close to full insurance 2 in second best arrangements agents organize in endogenous risk sharing islands in the network where shocks are shared fully within but imperfectly across islands as a result network based risk sharing is local socially closer agents insure each other more

wealth effects of foreign expansion by u s banks abstract the effects of foreign expansion on the market values of u s banks usbs are examined in this study the results show that shareholders of usbs experience significant abnormal returns of 0 17 percent when banks announce foreign expansions abnormal returns are insignificant when the announced mode of expansion is through a representative office are significantly positive for announcements related to branches and are significantly negative when the announced mode of expansion is through formation of a joint venture or a subsidiary or through an acquisition abnormal returns are significantly negative when banks announce expansion into developed countries and are significantly positive when announcements relate to risky developing countries post announcement changes in the total variance of returns and in the unsystematic risk of usbs are inversely related with abnormal returns higher wealth effects are associated with higher levels of prior overseas experience

the politics of underinvestment in agricultural research this paper develops a political economy framework that determines the factors causing underinvestment in public research expenditures governments are unable to fully compensate for unequal income distribution effects of research because of either their inability to make credible commitments or ofdeadweight costs associated with compensation

agricultural biotechnology the promise and prospects of genetically modified crops for millennia humans have modified plant genes in order to develop crops best suited for food fiber feed and energy production the earliest efforts far predating gregor mendel s 19th century discoveries on trait inheritance involved the selective breeding of plants with desirable characteristics but the recombination of dna in offspring was random consequently plant breeding often took decades and frequently yielded crop varieties with unforeseen and undesirable properties today conventional plant breeding remains inherently random and slow constrained by the availability of desirable traits in closely related plant species in contrast agricultural biotechnology employs the modern tools of genetic engineering to reduce uncertainty and breeding time and to transfer traits from more distantly related plants arguments in support of and in opposition to the use of genetically engineered seeds have changed little since the technology emerged in the 1980s on one side critics express concerns that the technology imposes negative environmental effects and jeopardizes the health of those who consume the frankenfoods on the other side supporters emphasize potential gains from boosting output and lowering food prices for consumers they argue that such gains are achieved contemporaneous with the adoption of farming practices that lower agrochemical use and lessen soil

does location matter for firms r d behaviour empirical evidence for danish firms in this paper we analyse whether regional location matters for danish firms r d performance in accordance with kleinknecht and poot s 1992 survey we test the urban hierarchy hypothesis stating that firms in urban agglomerations are more likely to perform r d than firms elsewhere using a micro dataset for danish firms obtained by merging danish r d statistics with account data the evidence of the influence of location on both the probability for undertaking r d and r d intensity is mixed but basically not in favour of any urban hierarchy in danish r d other non regional factors such as size of firm sectoral dummies classified according to pavitt s taxonomy and the dummy controlling for ict service industries are also estimated to have significant influence on firms r d behaviour furthermore the age of a firm only affects its r d intensity significantly cet article cherche a analyser si oui ou non la localisation regionale est importante pour le comportement des entreprises danoises quant