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

dynamic pricing in the presence of social learning and strategic consumers when a product of uncertain quality is first introduced consumers may choose to strategically delay their purchasing decisions in anticipation of the product reviews of their peers this paper investigates how the presence of social learning affects the strategic interaction between a dynamic pricing monopolist and a forward looking consumer population within a simple two period model our analysis yields three main insights first we find that the presence of social learning has significant structural implications for optimal pricing policies in the absence of social learning decreasing price plans are always preferred by the firm by contrast in the presence of social learning we find that i if the firm commits to a price path ex ante preannounced pricing an increasing price plan is typically announced whereas ii if the firm adjusts price dynamically responsive pricing prices are initially low and may either rise or decline over time second we establish that under both preannounced an

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

public goods in networks this paper considers incentives to provide goods that are non excludable along social or geographic links we find first that networks can lead to specialization in public good provision in every social network there is an equilibrium where some individuals contribute and others free ride in many networks this extreme is the only outcome second specialization can benefit society as a whole this outcome arises when contributors are linked collectively to many agents finally a new link increases access to public goods but reduces individual incentives to contribute hence overall welfare can be higher when there are holes in a network

pricing and the news vendor problem a review with extensions in the newsvendor problem a decision maker facing random demand for a perishable product decides how much of it to stock for a single selling period this simple problem with its intuitively appealing solution is a crucial building block of stochastic inventory theory which comprises a vast literature focusing on operational efficiency typically in this literature market parameters such as demand and selling price are exogenous however incorporating these factors into the mode l can provide an excellent vehicle for examining how operational problems interact with marketing issues to influence decision making at the firm level in this paper we examine an extension of the newsvendor problem in which stocking quantity and selling price are set simultaneously we provide a comprehensive review that synthesizes existing results for the single period problem and develop additional results to enrich the existing knowledge base we also review and develop insight into a dynamic inventory extension of this problem and motivate the applicability of such models

optimal pricing in networks with externalities we study the optimal pricing strategies of a monopolist selling a divisible good service to consumers who are embedded in a social network a key feature of our model is that consumers experience a positive local network effect in particular each consumer s usage level depends directly on the usage of her neighbors in the social network structure thus the monopolist s optimal pricing strategy may involve offering discounts to certain agents who have a central position in the underlying network our results can be summarized as follows first we consider a setting where the monopolist can offer individualized prices and derive a characterization of the optimal price for each consumer as a function of her network position in particular we show that it is optimal for the monopolist to charge each agent a price that consists of three components i a nominal term that is independent of the network structure ii a discount term proportional to the influence that this agent exerts over the rest of the social network quantified by the agent s bonacich centrality and iii a markup term proportional to the influence that the network exerts on the agent in the second part of the paper we discuss the optimal strategy of a monopolist who can only choose a single uniform price for the good and derive an algorithm polynomial in the number of agents to compute such a price third we assume that the monopolist can offer the good in two prices full and discounted and we study the problem of determining which set of consumers should be given the discount we show that the problem is np hard however we provide an explicit characterization of the set of agents who should be offered the discounted price next we describe an approximation algorithm for finding the optimal set of agents we show that if the profit is nonnegative under any feasible price allocation the algorithm guarantees at least 88 of the optimal profit finally we highlight the value of network information by comparing the profits of a monopolist who does not take into account the network effects when choosing her pricing policy to those of a monopolist who uses this information optimally

a long view of real rates in light of the large and sustained rise in real interest rates in the late 1970s and early 1980s this paper reviews i the theoretical discussion on the determination of nominal and real interest rates ii the factors determining real interest rates and iii problems of defining and measuring the real rate we go on to examine the historical record of real interest rates in france germany the uk and the usa since 1875 we find that high real rates since 1980 seem to be a return to a long run norm and it is the period from the second world war to 1979 that represents a more natural period in which to investigate an abrupt change of behaviour for real interest rates copyright 1999 by oxford university press

dispatch planning using newsvendor dual problems and occupation times application to hydropower abstract we consider price driven dispatch planning under price uncertainty a storable commodity is optimally sold and purchased over time first we consider models where the storage level is constrained in expectation the dual of the corresponding optimization problem is related to the newsvendor problem exact solutions of bang bang type are given the second methodology is for high frequency dispatch decisions in multistage stochastic programming models to overcome the curse of dimensionality prices are modeled by occupation times at price levels in a case study we consider a pumped storage hydropower plant numerical solutions are given which have similar patterns as for the first exactly solvable problems

north south lending and endogenous domestic capital market inefficiencies abstract we develop an open economy model of intertemporal trade under asymmetric information capital market imperfections are endogenous and depend on a country s stage of economic development relative to the perfect information benchmark north south capital flows are dampened and possibly reversed and world interest rates are lower whereas riskless rates are equalized across borders the domestic loan rate is higher in poorer countries the model can be applied to a number of policy issues including the debt overhang problem the indexation of foreign public debts and the effect of income distribution on growth

stochastic joint optimization of wind generation and pumped storage units in an electricity market one of the main characteristics of wind power is the inherent variability and unpredictability of the generation source even in the short term to cope with this drawback hydro pumped storage units have been proposed in the literature as a good complement to wind generation due to their ability to manage positive and negative energy imbalances over time this paper investigates the combined optimization of a wind farm and a pumped storage facility from the point of view of a generation company in a market environment the optimization model is formulated as a two stage stochastic programming problem with two random parameters market prices and wind generation the optimal bids for the day ahead spot market are the ldquohere and nowrdquo decisions while the optimal operation of the facilities are the recourse variables a joint configuration is modeled and compared with an uncoordinated operation a realistic example case is presented where the developed models are tested with satisfactory results

optimization of pumped storage capacity in an isolated power system with large renewable penetration this work describes an economic analysis of the inclusion of pumped storage in a small island system that has abundant renewable energy available but that at times cannot accept all of this power because of limits imposed by security criteria the question of whether or how much pumped storage to include is addressed by formulating a linear programming optimization problem the stochastic nature of load and renewable production is addressed using scenarios developed through fuzzy clustering both the unit capacity in mw and the reservoir storage capacity in mwh are optimized and optimal operating strategies for the scenarios are produced results showed that including pumped storage can be an effective means of allowing larger penetration of intermittent renewable energy sources improving both the dynamic security and the economic operation of a test system including the dynamic security criteria in the economic question of dimensioning the pumped storage unit proved to make a significant difference in the optimal pumped storage capacity

net foreign assets and international adjustment the united states japan and germany abstract this paper examines external adjustment in the usa japan and germany from the perspective of net foreign asset positions it asks two questions what are in the long run the determinants of net foreign asset equilibrium what are in the short run some of the adjustment mechanisms sustaining that equilibrium an analysis of post war data produces two insights first using a cointegration approach the existence of long run net foreign asset equilibrium can be identified it is a function of demographic variables and public debt second deviations from long run equilibrium give rise to feedback through different components of domestic absorption in the three countries

pricing in social networks we analyze the problem of optimal monopoly pricing in social networks where agents care about consumption or prices of their neighbors we characterize the relation between optimal prices and consumers centrality in the social network this relation depends on the market structure monopoly vs oligopoly and on the type of externalities consumption versus price we identify two situations where the monopolist does not discriminate across nodes in the network linear monopoly with consumption externalities and local monopolies with price externalities we also analyze the robustness of the analysis with respect to changes in demand and the introduction of bargaining between the monopolist and the consumer

bertrand competition under network externalities abstract two firms engage in price competition to attract buyers located on a network the value of the good of either firm to any buyer depends on the number of neighbors on the network who adopt the same good when the size of externalities increases linearly with the number of adoptions we identify the set of pricing strategies that are consistent with an equilibrium in which one of the firms monopolizes the market the set includes marginal cost mc pricing as well as bipartition pricing which offers discounts to some buyers and charges markups to others we show that mc pricing fails to be an equilibrium under non linear externalities in a general network but identify conditions for an equilibrium with bipartition pricing to be robust against perturbations in the externalities from linearity the analysis is applied to platform competition in a two sided market under local and approximately linear externalities

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

optimal pricing for a multinomial logit choice model with network effects we consider a seller s problem of determining revenue maximizing prices for an assortment of products that exhibit network effects customers make purchase decisions according to a multinomial logit choice model modified to incorporate network effects so that the utility each individual customer gains from purchasing a particular product depends on the market s total consumption of that product in the setting of homogeneous products we show that if the network effect is comparatively weak then the optimal pricing decision of the seller is to set identical prices for all products however if the network effect is strong then the optimal pricing decision is to set the price of one product low and to set the prices of all other products to a single high value this boosts the sales of the single low price product in comparison to the sales of all other products we also obtain comparative statics results that describe how optimal prices and sales levels vary with a parameter that determines the strengt

estimating the value of electricity storage in pjm arbitrage and some welfare effects significant increases in prices and price volatility of natural gas and electricity have raised interest in the potential economic opportunities for electricity storage in this paper we analyze the arbitrage value of a price taking storage device in pjm during the six year period from 2002 to 2007 to understand the impact of fuel prices transmission constraints efficiency storage capacity and fuel mix the impact of load shifting for larger amounts of storage where reductions in arbitrage are offset by shifts in consumer and producer surplus as well as increases in social welfare from a variety of sources is also considered

technology adoption in the presence of network externalities we analyze technology adoption in industries where network externalities are significant the pattern of adoption depends on whether technologies are sponsored a sponsor is an entity that has property rights to the technology and hence is willing to make investments to promote it key findings include the following 1 compatibility tends to be undersupplied by the market but excessive standardization can occur 2 in the absence of sponsors the technology superior today has a strategic advantage and is likely to dominate the market 3 when one of two rival technologies is sponsored that technology has a strategic advantage and may be adopted even if it is inferior 4 when two competing technologies both are sponsored the technology that will be superior tomorrow has a strategic advantage

competitive energy storage in the presence of renewables a large fraction of new distributed generation will use renewable sources and cannot be treated as conventional generators due to high variability energy storage is a natural mechanism for absorbing variability and hence minimizing costly reliance on generator reserves we consider a simple scenario in which energy imbalances are allocated to energy storage representing either cooperation with a renewable producer or competitive operation in markets the optimal storage scheduling strategy is shown to be an inventory control like policy which through mild approximation yields affine relationships with the state variables we develop and numerically evaluate suboptimal policies that approximately incorporate the effects of correlation further approximation enables us to characterize the nash equilibria arising between generation and storage which we use to analyze strategic effects specifically we find that inefficient storage can lead to non socially optimal behavior

bootstrap inference in econometrics the astonishing increase in computer performance over the past two decades has made it possible for economists to base many statistical inferences on simulated or bootstrap distributions rather than on distributions obtained from asymptotic theory in this paper i review some of the basic ideas of bootstrap inference the paper discusses monte carlo tests several types of bootstrap test and bootstrap confidence intervals although bootstrapping often works well it does not do so in every case

can a wind farm with caes survive in the day ahead market abstract we investigate the economic viability of coupling a wind farm with compressed air energy storage caes to participate in the day ahead electricity market at a time when renewable portfolio standards are not binding and wind competes freely in the marketplace in our model the caes is used to reduce the risk of committing uncertain quantities of wind energy and to shift dispatch of wind generation to high price periods other sources of revenue capacity markets ancillary services price arbitrage are not included in the analysis we present a model to calculate profit maximizing day ahead dispatch schedules based on wind forecasts annual profits are determined with dispatch schedules and actual wind generation values we find that annual income for the modeled wind caes system would not cover annualized capital costs using market prices from the years 2006 to 2009 we also estimate market prices with a carbon price of 20 and 50 per tonne co2 and find that revenue would still not cover the capital costs the implied cost per tonne of avoided co2 to make a wind caes profitable from trading on the day ahead market is roughly 100 with large variability due to electric power prices

competitive targeted advertising over networks recent advances in information technology have allowed firms to gather vast amounts of data regarding consumers preferences and the structure and intensity of their social interactions this paper examines a game theoretic model of competition between firms that can target their marketing budgets to individuals embedded in a social network we provide a sharp characterization of the optimal targeted advertising strategies and highlight their dependence on the underlying social network structure furthermore we provide conditions under which it is optimal for the firms to asymmetrically target a subset of the individuals and establish a lower bound on the ratio of their payoffs in these asymmetric equilibria finally we find that at equilibrium firms invest inefficiently high in targeted advertising and the extent of the inefficiency is increasing in the centralities of the agents they target taken together these findings shed light on the effect of the network structure on the outcome of marketing co

what drives long term capital flows a theoretical and empirical investigation abstract what drives capital inflows in the long run this paper illustrates how capital movements conform surprisingly well to the predictions of a neoclassical model with credit constraints the most intriguing prediction of this class of models is that contrary to a pure neoclassical model domestic saving should act as a complement rather than a substitute to capital inflows nevertheless this class of models keeps the neoclassical prediction that capital should flow to countries where it is most scarce using foreign debt data from 1970 to 1998 i find qualitative and quantitative evidence that supports these predictions

optimal management and sizing of energy storage under dynamic pricing for the efficient integration of renewable energy we address the optimal energy storage management and sizing problem in the presence of renewable energy and dynamic pricing associated with electricity from the grid we formulate the problem as a stochastic dynamic program that aims to minimize the long run average cost of electricity used and investment in storage if any while satisfying all the demand we model storage with ramp constraints conversion losses dissipation losses and an investment cost we prove the existence of an optimal storage management policy under mild assumptions and show that it has a dual threshold structure under this policy we derive structural results which indicate that the marginal value from storage decreases with its size and that the optimal storage size can be computed efficiently we prove a rather surprising result as we characterize the maximum value of storage under constant prices and i i d net demand processes if the storage is a profitable investment then the ratio of the amortized cost of storage to the constant price is less than 1 4 we further perform sensitivity analysis on the size of optimal storage and its gain via a case study finally with a computational study on real data we demonstrate significant savings with energy storage

the external wealth of nations measures of foreign assets and liabilities for industrial and developing countries abstract although capital flows are closely monitored surprisingly little is known about the accumulated stocks of foreign assets and liabilities held by various countries especially in the developing world this paper constructs estimates of foreign assets and liabilities and their equity and debt subcomponents for a sample of 67 industrial and developing countries it characterizes the stylized facts of international balance sheets and asks whether there are trends in net foreign asset positions and shifts in debt equity ratios over time finally it explores the sensitivity of estimated stock positions to the treatment of valuation effects not captured in balance of payments data

economic valuation of reserves in power systems with high penetration of wind power this paper proposes a methodology to determine the required level of spinning and nonspinning reserves in a power system with a high penetration of wind power the computation of the required reserve levels and their costs is achieved through a stochastic programming market clearing model spanning a daily time horizon this model considers the network constraints and takes into account the cost of both the load shedding and the wind spillage the methodology proposed is illustrated using an example and a realistic case study some conclusions are finally drawn

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

the cost of segregation in social networks abstract this paper investigates the welfare effect of income redistribution in the private provision of public goods on networks we first show that the welfare effect of income redistribution is determined by bonacich centrality then we develop an index based on the network structure of interactions which roughly speaking measures the welfare effect of income redistribution confined to a component of contributors the proposed index vanishes when applied to large components of contributors that display special segregated interactions which suggests an asymptotic neutrality of redistributive policies

optimal energy commitments with storage and intermittent supply we formulate and solve the problem of making advance energy commitments for wind farms in the presence of a storage device with conversion losses mean reverting price process and an autoregressive energy generation process from wind we derive an optimal commitment policy under the assumption that wind energy is uniformly distributed then the stationary distribution of the storage level corresponding to the optimal policy is obtained from which the economic value of the storage as the relative increase in the expected revenue due to the existence of storage is obtained

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

on the private provision of public goods on networks abstract this paper analyzes the private provision of public goods where consumers interact within a fixed network structure and may benefit only from their direct neighbors provisions we present a proof of the existence and uniqueness of a nash equilibrium for general networks and best reply functions in addition we investigate the neutrality result of warr 38 and bergstrom blume and varian 6 whereby consumers are able to undo the impact of income redistribution as well as public provision financed by lump sum taxes to this effect we show that the neutrality result has a limited scope of application beyond a special network architecture in the neighborhood of the set of contributors

optimal contracting in networks abstract we study optimal contracting between a firm selling a divisible good that exhibits positive externality and a group of agents in a social network the extent of externality that each agent receives from the consumption of neighboring agents is privately held and is unknown to the firm by explicitly characterizing the optimal multilateral contract we demonstrate how inefficiency in an agent s trade propagates through the network and creates unequal and network dependent downward distortion in other agents trades furthermore we describe bilateral contracts non linear pricing schemes and characterize their explicit dependence on the network structure we show that the firm will benefit from uncertainty in an agent s valuation of other agents externality we describe the profit gap between multilateral and bilateral contracts and analyze the consequences of the explicit dependence of the contracts on network structure when the network is balanced in terms of homogeneity of agents influence network structure has no impact on the firm s profit for bilateral contracts on the other hand when the influences are heterogeneous with high dispersion as in core periphery networks the restriction to bilateral contracts can result in profit losses that grow unbounded with the size of networks

why doesn t capital flow from rich to poor countries an empirical investigation we examine the empirical role of difierent explanations for the lack of ows of capital from rich to poor countries the lucas paradox the theoretical explanations include difierences in fundamentals across countries and capital market imperfections we show that during 1970i2000 low institutional quality is the leading explanation for example improving peru s institutional quality to australia s level implies a quadrupling of foreign investment recent studies emphasize the role of institutions for achieving higher levels of income but remain silent on the speciflc mechanisms our results indicate that foreign investment might be a channel through which institutions afiect long run development

mechanism and network design with private negative externalities a revenue maximizing monopolist is selling a single indivisible good to buyers who face a loss if any of its rival buyers obtain it the rivalry is modeled through a network an arc between a pair of buyers indicates that a buyer considers another buyer its rival and the magnitude of the loss is the private information of each buyer this loss exposure due to competitive considerations can be viewed as a negative externality first using a myersonian approach we derive the monopolist s optimal mechanism for any given network second we show that revenues depend on the network structure thus in applications where it is possible the monopolist might consider designing not only the mechanism but also the network if not fully at least partially third we provide and fully describe the solution to the monopolist s market design problem that is the joint network and mechanism design problem specifically despite the nonmonotone impact of additional competition on the monopolist s revenues we deter