Innovation and growth through local and global interaction

This paper investigates the research and development activity of heterogeneous and rationally bounded firms. The latter conduct this activity through in-house research and by collecting information originating in other firms’ spillovers. Thus, research and development activity owes both to independent searching and to interaction diffusing information. We study the conditions under which this idiosyncratic effort yields effects that have either local, system-wise negligible impacts or cumulate to generate significant aggregate ones. In the latter case, global effects feed back upon the incentive to innovate and therefore on the strength of local interaction as well as on autonomous research efforts. It is these dynamic forces that we model. We compare cases in which significant aggregate effects do emerge with cases in which they do not and study their outcome on innovation-directed investment and on long-term growth.     

EFFECTS OF SECTOR AGGREGATION ON CO2 MULTIPLIERS IN MULTIREGIONAL INPUT–OUTPUT ANALYSES

The past few years have seen the emergence of several global multiregional input–output (MRIO) databases. Due to the cost and complexity of developing such extensive tables, industry sectors are generally represented at a rather aggregate level. Currently, one of the most important applications of input–output analysis is environmental assessments, for which highly aggregate sectors may not be sufficient to yield accurate results. We experiment with four of the most important global MRIO systems available, analyzing the sensitivity of a set of aggregate CO₂ multipliers to aggregations in the MRIO tables used to calculate them. Across databases, we find (a) significant sensitivity to background system detail and (b) that sub-sectors contained within the same aggregate MRIO sector may exhibit highly different carbon multipliers. We conclude that the additional information provided by the extra sector detail may warrant the additional costs of compilation, due to the heterogeneous nature of economic sectors in terms of their environmental characteristics.     

Aggregate vs. disaggregate data analysis—a paradox in the estimation of a money demand function of Japan under the low interest rate policy

We use Japanese aggregate and disaggregate money demand data to show that conflicting inferences can arise. The aggregate data appears to support the contention that there was no stable money demand function. The disaggregate data shows that there was a stable money demand function. Neither was there any indication of the presence of a liquidity trap. Possible sources of discrepancy are explored and the diametrically opposite results between the aggregate and disaggregate analysis are attributed to the neglected heterogeneity among micro units. We provide necessary and sufficient conditions for the existence of a cointegrating relation among aggregate variables when heterogeneous cointegration relations among micro units exist. We also conduct simulation analysis to show that when such conditions are violated, it is possible to observe stable micro relations, but unit root phenomena among macro variables. Moreover, the prediction of aggregate outcomes, using aggregate data, is less accurate than the prediction based on micro equations, and policy evaluation based on aggregate data ignoring heterogeneity in micro units can be grossly misleading. Copyright © 2005 John Wiley & Sons, Ltd.     

Optimal policy in a model of endogenous fluctuations and assets

Assets are coupled to endogenous aggregate output fluctuations in a model of heterogeneous agents. Those agents wish to avoid reacting inadvertently to an unobservable noise process, but to do so must elicit reactions to that noise from each other. An abstract institution is modeled that optimizes this elicitation by strategically transmitting information about aggregates; I designate this feedback. Feedback is used by agents and so influences the characteristics of aggregate fluctuations. The optimal feedback policy minimizes asset rates of return, maximizes the persistence of aggregate output fluctuations, and causes the distribution of wealth to widen continually and without limit.     

Solving the incomplete markets model with aggregate uncertainty using the Krusell–Smith algorithm

This paper studies the properties of the solution to the heterogeneous agents model in Den Haan et al. [2009. Computational suite of models with heterogeneous agents: incomplete markets and aggregate uncertainty. Journal of Economic Dynamics and Control, this issue]. To solve for the individual policy rules, we use an Euler-equation method iterating on a grid of pre-specified points. To compute the aggregate law of motion, we use the stochastic-simulation approach of Krusell and Smith [1998. Income and wealth heterogeneity in the macroeconomy. Journal of Political Economy 106, 868–896]. We also compare the stochastic- and non-stochastic-simulation versions of the Krusell–Smith algorithm, and we find that the two versions are similar in terms of their speed and accuracy.     

Solving the incomplete markets model with aggregate uncertainty using explicit aggregation

We propose a method to solve models with heterogeneous agents and aggregate uncertainty. The law of motion describing aggregate behavior is obtained by explicitly aggregating the individual policy rule. The algorithm is simpler and faster than existing algorithms that rely on parameterization of the cross-sectional distribution and/or a computationally intensive simulation step. Explicit aggregation establishes a link between the individual policy rule and the set of necessary aggregate state variables, an insight that can be helpful in determining what state variables to include in other algorithms as well.     

Micro versus macro cointegration in heterogeneous panels

We consider the issue of cross-sectional aggregation in nonstationary and heterogeneous panels where each unit cointegrates. We derive asymptotic properties of the aggregate estimate, and necessary and sufficient conditions for cointegration to hold in the aggregate relationship. We then analyze the case when cointegration does not carry through the aggregation process, and we investigate whether the violation of the formal conditions for perfect aggregation can still lead to an aggregate equation that is observationally equivalent to a cointegrated relationship. We derive a measure of the degree of noncointegration of the aggregate relationship and we explore its asymptotic properties. We propose a valid bootstrap approximation of the test. A Monte Carlo exercise evaluates size and power properties of the bootstrap test.     

An optimistic search equilibrium

We study a market search equilibrium with aggregate uncertainty, private information and heterogeneous beliefs that are initially optimistic. Despite these biased beliefs, it is shown that all optimistic equilibria converge to perfect competition in the limit as the time between matches tends to 0.     

What inventories tell us about aggregate fluctuations—A tractable approach to (S,s) policies

We estimate a DSGE model with (S,s) inventory policies. We find that (i) taking inventories into account can significantly improve the empirical fit of DSGE models in matching the standard business-cycle moments (in addition to explaining inventory fluctuations); (ii) (S,s) inventory policies can significantly amplify aggregate output fluctuations, in contrast to the findings of the recent general-equilibrium inventory literature; and (iii) aggregate demand shocks become more important than technology shocks in explaining the business cycle once inventories are incorporated into the model. An independent contribution of our paper is that we develop a solution method for analytically solving (S,s) inventory policies in general equilibrium models with heterogeneous firms and a large aggregate state space, and we illustrate how standard log-linearization methods can be used to solve various versions of our inventory model, generate impulse response functions, and estimate the model׳s deep structural parameters.     

Sustainable financing practices through green bonds: What affects the funding size?

Financing through the supply‐driven green bonds market has significantly surged in recent years. In this paper, we examine the factors influencing the size of financing though green bond supply, using cross‐section OLS regressions on a global dataset for 8 years (2010–2017) sourced from Bloomberg. We consider a set of tridimensional factors: bond characteristics, issuer characteristics, and market characteristics and examine their effects on issue size. Alongside whole sample estimation, we produce year‐wise estimations to realize the evolution and persistence of the effects over time. We then produce estimates across rating grades of the bonds. Finally, we carry Blinder–Oaxaca decomposition to see if average issue size has significantly changed over time and whether the factors considered can explain the difference. We find a large number of factors affecting issue size asymmetrically; however, many of the effects do not persist over time and are heterogeneous across rating grades. In contrast to the aggregate market trend, we find no evidence of increases in average issue size in the recent year. Furthermore, the average financing size is found significantly lower for high‐grade bonds. The paper provides a basis for encouraging green bond supply, particularly considering the rating of the bonds and the issuers.     

虚拟交互对提高教学交互程度增强教学效果的研究

当前教学交互存在的问题:第一,内容交互不足。其次,网络课程交互性不足;第二,人际交互不够。学生参与交互活动的频率少。论坛话题漂移。交互的内容主要是学科知识﹑情感交流很少。网络教师的教﹑辅分离。忽视学习社区的建设﹑营造协作学习环境不够。我们可以建立虚拟教学交互系统。我们的教学交互摒弃空洞无物的交互技术,将交互建立在充实的内容基础上;其次,要使交互具有良好的问题反应能力,力求使学习者的所有问题都能得到及时的反馈和评价。加强实时交互,充分提高教学交互程度。     

A practical log‐linear aggregation method with examples: heterogeneous income growth in the USA

A practical aggregation method for heterogeneous log‐linear functions is presented. Inequality measures are employed in the construction of a simple but exact aggregate representation of an economy. Three macroeconomic applications are discussed: the aggregation of the Lucas supply function, the time‐inconsistent behaviour of an egalitarian social planner facing heterogeneous discount rates, and the case of a simple heterogeneous growth model. In the latter application, aggregate CPS data is used to show that the slowdown that followed the first oil shock is worse than usually thought, and that the ‘new economy’ growth resurgence is not as strong as it appears.

相似文献   

Reducing omitted-variable bias in spatial-interaction models by considering multiple neighbourhoods

ABSTRACT

A major challenge in the analysis of micro-level spatial interaction is to distinguish actual interactions from the effects of spatially correlated omitted variables. We propose extending the simple spatially lagged explanatory (SLX) model to include two spatial weighting matrices at different spatial scales to reduce omitted-variable bias. The approach is suitable when actual interaction takes place on a smaller local level, while the omitted variables are spatially correlated at a larger regional level and correlated with the included characteristics. We provide an empirical motivation and use Monte Carlo simulation to illustrate the bias-reduction effects in certain settings.     

Social norms,coordination and collaboration in heterogeneous teams

This paper considers the coordinating role of social norms in a heterogeneous team of workers. We define an optimal unit of production as a form of organisation involving several teams and members, with the following properties: (i) a social norm operating to coordinate individual efforts; (ii) a team with heterogeneous skills, enabling generation of synergies. Our model suggests that competences of the best worker are transferred to his or her peers. This collaborative process enhances team efficiency but only if there is an implicit ex ante coordinating device based on social norms that discourage free riding. Copyright © 2008 John Wiley & Sons, Ltd.     

INDIVIDUAL VERSUS AGGREGATE INCOME ELASTICITIES FOR HETEROGENEOUS POPULATIONS

This paper deals with different concepts of income elasticities of demand for a heterogeneous population and the relationship between individual and aggregate elasticities. In general, the aggregate elasticity is not equal to the mean of individual elasticities. The difference depends on the heterogeneity of the population and is quantified by a covariance term. Sign and magnitude of this term are determined by an empirical analysis based on the UK Family Expenditure Survey. It is shown that the relevant quantities can be identified from cross‐sectional data and, without imposing restrictive structural assumptions, can be estimated by nonparametric techniques. It turns out that the aggregate elasticity significantly overestimates the mean of individual elasticities for many commodity groups. Copyright © 2011 John Wiley & Sons, Ltd.     

Aggregate productivity losses from factor misallocation across Chinese manufacturing firms

Aggregate productivity can be largely determined by how efficiently production factors are allocated across heterogeneous establishments. This paper estimates aggregate productivity losses from factor misallocation using a large sample of Chinese manufacturing firms. We analyze the institutional background and provide some stylized facts on factor misallocation of capital and labor in China. Using an approximation method based on the estimation of input gaps, we find that aggregate productivity losses reach an average rate of 11.18 percentage points per year. On average, capital and labor misallocation account for 6.73 and 4.45 percentage points, respectively. State ownership plays an important role in generating factor misallocation and productivity losses. Our results imply that factor misallocation have become a major obstacle preventing China from moving to a more efficient economy.     

A threshold theory of discretionary interaction behavior

There presently exists a gap between aggregate and disaggregate approaches to modeling spatial interaction behavior. This paper proposes a strategy for filling this gap by focusing on specific types of interaction behavior which share certain common characteristics. In the present case, a simple threshold theory is developed which establishes a link between various types of discretionary interaction behavior by individuals and the resulting macro distribution of interaction frequencies. In particular, it is shown that if the statistical population of potential interaction situations satisfies certain independence conditions over space, then the resulting macro interaction frequencies are always Poisson distributed with mean frequency levels representable by a classical gravity model.     

Consumption and labor supply

We present a new econometric model of aggregate demand and labor supply for the United States. We also analyze the allocation full wealth among time periods for households distinguished by a variety of demographic characteristics. The model is estimated using micro-level data from the Consumer Expenditure Surveys supplemented with price information obtained from the Consumer Price Index. An important feature of our approach is that aggregate demands and labor supply can be represented in closed form while accounting for the substantial heterogeneity in behavior that is found in household-level data. As a result, we are able to explain the patterns of aggregate demand and labor supply in the data despite using a parametrically parsimonious specification.     

Social distance,heterogeneity and social interactions

A crucial ingredient in social interaction models is the structure of peer groups, which link individuals with similar characteristics. We propose and study a dynamic binary choice model with social interactions in which heterogeneity of peer group effects is modeled introducing diversity in individual characteristics and linking pairwise influences to a social distance between individuals. Our framework allows for mimetic as well as anti-mimetic interactions and a heterogeneous structure of peer groups across individuals. Dynamic equilibria are studied in the limit when the number of agents is large. We show that the model exhibits multiple equilibria resulting from conflicts between various group pressures the individuals are subjected to. We study in particular the correlation in the population at equilibrium between the characteristics of the agents and their decisions: this quantity has an interesting empirical interpretation and solves a simple analytical equation when the number of agents is large. Finally we discuss the empirical content of the model and present a consistent estimator for the parameter describing which is consistent for any typical population regardless of the structure of individual characteristics.     

On measuring patterns of neighbourly relationships

This paper focuses on certain geographical aspects of social interaction and in particular on the problems of measuring patterns of social relationships between people. First the relevant characteristics of neighbourly interactions are examined, and the distinction drawn between studies at individual and aggregate levels respectively. The concern subsequently is primarily with the measurement problems at the aggregate or group level, and a technique for analysing patterns of social relations is described called the standard deviational ellipse. Drawing upon research which has recently been carried out in selected neighbourhoods of the City of Cardiff, the paper discusses the utility of this method for analysing the eommunality in patterns of neighbourly interaction as a basis for generalisation, and argues the case for further social-geographical research in this field.