New monetarism with endogenous product variety and monopolistic competition

I examine the role played by endogenous variety and monopolistic competition in the long-run transmission of monetary policy. I integrate free entry, product variety and monopolistic competition into a New Monetarist framework, considering preferences that give rise to either constant or variable markups. I find that inflation generally reduces variety. Under CES preferences, firms are inefficiently small, with the inefficiency increasing with product differentiation and the extent of search frictions. The Friedman rule is the best policy under CES preferences. In contrast, with variable elasticity of demand, inflation can increase firm size, reduce markups, and raise welfare, even though output is lower. Under CES preferences, the welfare cost of inflation is high; moreover, this cost increases monotonically with the markup and is higher with endogenous variety than with a fixed product space.     

Generic non-existence of general equilibrium with EUU preferences under extreme ambiguity

In the presence of three or more realisations of the aggregate endowment that are extremely ambiguous, in the sense that all relative probabilities are admissible, if agents have preferences that are representable by expected uncertain utility functions (Gul and Pesendorfer, 2014), general equilibrium does not generically exist in finite economies. It always exists, however, in continuum economies.     

Consumer surplus analysis under uncertainty: A general equilibrium perspective

This paper derives an exact form of partial equilibrium efficiency measure under uncertainty which is consistent with expected utility maximization in a general equilibrium situation with ex-post spot markets for many goods and asset markets which are in general incomplete.We consider that the good under consideration tends to be negligibly small compared to the entire set of commodity characteristics which is assumed to be a continuum, and look into the limit property of preferences over state-contingent consumption of the good and state-contingent income transfer associated to it. We show that the limit preference exhibits risk neutrality, not only that it exhibits no income effect, meaning that the two conditions are tied together. We also show that the marginal rate of substitution between extra income transfers at different states of the world converges to the ratio between the Lagrange multipliers associated to those states. When the asset markets are complete such ratios are equalized between consumers, but it is not the case in general when the asset markets are incomplete. This means that using the aggregate expected consumer surplus as the welfare measure will be in general inconsistent with individuals’ expected utility maximization in the general equilibrium environment or with ex-ante Pareto efficiency.     

A cobweb model of land-use competition between food and bioenergy crops

We present a model of interacting cobweb markets and apply it to land-use competition between food and bioenergy crops. In our model the markets are interlinked on the supply side by the limited availability of land. Therefore, instabilities are transferred between the markets and we find that bioenergy demand affects food price volatility. The agents in the model have heterogeneous production capacities, representing variation in global land quality. When we allow agents to choose price predictor, we find that a more sophisticated (but costly) predictor is concentrated to some key parcels of land, which enables the system to reduce instability significantly. The system can also be brought closer to a stable state by introducing costs for changing production type, but it may then be shifted away from the optimum situation predicted by the corresponding equilibrium model.     

An existence theorem for Cournot–Walras equilibria in a monopolistically competitive economy

We establish an existence theorem for Cournot–Walras equilibria in a monopolistically competitive economy. Instead of the traditional approach which depends on Kakutani’s fixed point theorem, we employ the theories of aggregative games and best reply potential games. We show that, if there exists a representative consumer, under some conditions on preferences and production technologies, the profit maximization game is a (pseudo) best reply potential game. Hence, the existence of the equilibria is proved independently of the well known convex-valued assumption on the best responses. Although our assumptions result in the additive separability on a utility function of a representative consumer, the existence of increasing returns and indivisible productions can be allowed. In our model, it is shown that the game played by firms exhibits strategic substitutes whether the products of firms are substitutes or complements, and this plays an important role for the existence of the equilibria.     

Perturbed utility and general equilibrium analysis

We study general equilibrium theory of complete markets in an otherwise standard economy with each household having an additive perturbed utility function. Since this function represents a type of stochastic choice theory, the equilibrium of the corresponding economy is defined to be a price vector that makes its mean expected demand equal its mean endowment. We begin with a study of the economic meaning of this notion, by showing that at any given price vector, there always exists an economy with deterministic utilities whose mean demand is just the mean expected demand of our economy with additive perturbed utilities. We then show the existence of equilibrium, its Pareto inefficiency, and the upper hemi-continuity of the equilibrium set correspondence. Specializing to the case of regular economies, we finally demonstrate that almost every economy is regular and the equilibrium set correspondence in this regular case is continuous and locally constant.     

A general equilibrium analysis of strategic arbitrage

We analyze a general equilibrium framework with Cournot arbitrageurs and with price-taking investors who are subjected to restricted participation constraints. Restricted participation may leave some arbitrage opportunities unexploited by investors.We show existence of Cournot–Walras equilibria with an endogenous number of arbitrageurs. The number of arbitrageurs is endogenous since they have to sink entry costs in order to arbitrage across the relevant markets. We characterize equilibria and analyze the effects on equilibrium prices and quantities of increased competition among arbitrageurs due to lower entry costs.     

Energy balance climate models and general equilibrium optimal mitigation policies

In a general equilibrium model of the world economy, we develop a two-dimensional energy balance climate model featuring heat diffusion and anthropogenic forcing driven by global fossil fuel use across the sphere of the Earth. This introduces an endogenous location dependent temperature function, driving spatial characteristics, in terms of location dependent damages resulting from local temperature anomalies into the standard climate-economy framework. We solve the social planner's problem and characterize the competitive equilibrium for two polar cases differentiated by the degree of market integration. We define optimal taxes on fossil fuel use and how they may implement the planning solution. Our results suggest that if the implementation of international transfers across latitudes is not possible then optimal taxes are in general spatially non-homogeneous and may be lower at poorer latitudes. The degree of spatial differentiation of optimal taxes depends on heat transportation. By employing the properties of the spatial model, we show by numerical simulations how the impact of thermal transport across latitudes on welfare can be studied.     

Bilateral trade between India and Bangladesh: A general equilibrium approach

India and Bangladesh have pursued policies of trade liberalization since the early 1990s. However, owing to the differential speeds of opening up, Bangladesh's bilateral trade deficit with India widened substantially over the years. This aggravated the economic and the political tensions between the economies. It has been held that promotion of free trade between the two economies may enhance the trade and hence economic cooperation between them. Against this backdrop the present paper proposes a theoretical framework that provides a general equilibrium determination of the commodity pattern of trade and hence locates the comparative advantages of the economies. The empirical implementation of the model considers trade in 25 sectors comparable in the input–output tables of the economies. The study isolates the gains from free trade accruing to either economy. The paper also explores the pattern of bilateral trade when each economy produces goods by utilizing their own as well as the other country's technology. The gains from this trading arrangement are also isolated.     

Existence of an equilibrium for infinite horizon economies with and without complete information

This work proves the existence of an equilibrium for an infinite horizon economy where trade takes place sequentially over time. There exist two types of agents: the first correctly anticipates all future contingent endogenous variables with complete information as in Radner [Radner, R. (1972). Existence of equilibrium of plans, prices and price expectations in a sequence of markets. Econometrica, 289–303] and the second has exogenous expectations about the future environment as in Grandmont [Grandmont, J. M. (1977). Temporary general equilibrium theory. Econometrica, 535–572] and information based on the current and past aggregate variables including those which are private knowledge. Agents with exogenous expectations may have inconsistent optimal plans but have predictive beliefs in the context of Blackwell and Dubbins [Blackwell, D., Dubins, L. (1962). Merging of opinions with increasing information. The Annals of Mathematical Statistics, 882–886] with probability transition rules based on all observed variables. We provide examples of this framework applied to models of differential information and environments exhibiting results of market selection and convergence of an equilibrium. The existence result can be used to conclude that, by adding the continuity assumption on the probability transition rules, we obtain the existence of an equilibrium for some models of differential information and incomplete markets.     

Stability of a Cournot-Nash equilibrium: The multiproduct case

This paper examines the stability conditions of Cournot-Nash equilibria in models in which each firm produces multiple outputs in m related markets. Using a discrete adjustment process, we establish sufficient and necessary conditions for stability. We derive further specialized stability conditions for three important cases, namely a multiproduct duopoly, a multiproduct oligopoly with homogeneous products, and a single-product oligopoly with product heterogeneity. The paper shows that the stability conditions of the m markets individually are in general sufficient nor necessary for the stability of the m markets as a group. In addition, an example is given of how the stability conditions can be applied to determine comparative statics for multiproduct oligopoly.     

On the emergence of scale-free production networks

We propose a simple dynamical model for the formation of production networks among monopolistically competitive firms. The model subsumes the standard general equilibrium approach à la Arrow–Debreu but displays a wide set of potential dynamic behaviors. It robustly reproduces key stylized facts of firms׳ demographics. Our main result is that competition between intermediate good producers generically leads to the emergence of scale-free production networks.     

Agglomeration under forward-looking expectations: Potentials and global stability

This paper considers a class of migration dynamics with forward-looking agents in a multi-country solvable variant of the core–periphery model of Krugman [Krugman, P., 1991. Increasing returns and economic geography. Journal of Political Economy 99, 483–499]. We find that, under a symmetric externality assumption, our static model admits a potential function, which allows us to identify a stationary state that is uniquely absorbing and globally accessible under the perfect foresight dynamics whenever the degree of friction in relocation decisions is sufficiently small. In particular, when trade barriers are low enough, full agglomeration in the country with the highest barrier is the unique stable state for small frictions. New aspects in trade and tax policy that arise due to forward-looking behavior are discussed.     

On the robustness of the competitive equilibrium: Utility-improvements and equilibrium points

We show that the set of competitive equilibrium points of a pure exchange economy are the equilibrium points of a broader class of better-response demands than the usual utility-maximizing demand functions. The better-response demands are derived from assigning weights to all commodity bundles with higher utility than the current commodity bundle, with the greatest weights being placed on the commodity bundles with the highest utility gain. The usual utility-maximizing demand functions are then those in which the weight on the utility-maximizing bundle is one. We also show that these better-response demands belong to a large class of response maps that are generated by monotonic transformations of the utility functions and/or monotonic transformations of the weights assigned to the commodity bundles.     

层次分析法在合作竞争下供应商选择中的应用

文章用层次分析法构造了合作竞争下选择零部件供应商的评价模型,并结合实例详述了这种方法的应用。     

Interregional tax competition and intraregional political competition: The optimal provision of public goods under representative democracy

This paper explores the implications of the interaction between interregional tax competition and intraregional political competition for the optimal provision of public goods under representative democracy à la (Osborne and Slivinski, 1996) and (Besley and Coate, 1997). As an extension of Hoyt’s (1991) finding that intensified tax competition is always harmful and aggravates the extent to which public goods are undersupplied in a region, we show that intensified tax competition can be beneficial if political as well as tax competition is considered. In particular, we identify plausible conditions under which (i) there is an optimal intensity of tax competition such that the interaction between interregional tax competition and intraregional political competition will result in the optimal provision of public goods and (ii) intensified tax competition will be beneficial if and only if the degree of tax competition is less than this optimal intensity.     

Incorporating sustainability indicators into a computable general equilibrium model of the scottish economy

In recent years, the notion of sustainable development has begun to figure prominently in the regional, as well as the national, policy concerns of many industrialized countries. Indicators have typically been used to monitor changes in economic, environmental and social variables to show whether economic development is on a sustainable path. In this paper we endogenize individual and composite environmental indicators within an appropriately specified computable general equilibrium modelling framework for Scotland. In principle, at least, this represents a very powerful modelling tool that can inform the policy making process by identifying the impact of any exogenous policy change on the key endogenous environmental and economic indicators. It can also identify the effects of any binding environmental targets on economic activity.     

Applicability of a spatial computable general equilibrium model to assess the short-term economic impact of natural disasters

Computable general equilibrium (CGE) models have been widely used to assess the economic impact of natural disasters, but the models have not been fully validated by applying them to real disasters. This study focuses on validating a model for use in a short-run case in which the functional recovery of infrastructure and businesses occurred on a time scale of a few months. A special attempt is made to determine the parameter values of elasticity of substitutions, which play an important role in the effect on supply chains. In this study, a spatial CGE model, in which Japan is divided into nine regions, is constructed and applied to the case of the 2011 Great East Japan Earthquake and Tsunami. Through this application, the best estimates of the elasticity parameters generated relatively consistent estimates of production change compared with the observed change, both in severely affected regions and in other regions.     

A statistical equilibrium model of competitive firms

We find that the empirical density of firm profit rates, measured as returns on assets, is markedly non-Gaussian and reasonably well described by an exponential power (or Subbotin) distribution. We start from a statistical equilibrium model that leads to a stationary Subbotin density in the presence of complex interactions among competitive heterogeneous firms. To investigate the dynamics of firm profitability, we construct a diffusion process that has the Subbotin distribution as its stationary probability density. This leads to a phenomenologically inspired interpretation of variations in the shape parameter of the Subbotin distribution, which essentially measures the competitive pressure in and across industries. Our findings have profound implications both for the previous literature on the ‘persistence of profits’ as well as for understanding competition as a dynamic process. Our main formal finding is that firms' idiosyncratic efforts and the tendency for competition to equalize profit rates are two sides of the same coin, and that a ratio of these two effects ultimately determines the dispersion of the equilibrium distribution.