Spatial Competition and Shopping Externalities: Evidence from the Housing Market

In search markets, greater spatial concentration of sellers increases price competition. At the same time, though, a greater concentration of sellers can create a shopping externality by attracting more buyers to the site. Using housing sales data, we test for spatial competition and shopping externality effects on prices and marketing time. We find that they reflect both competitive and shopping externality effects from surrounding houses, although the relative strength varies with how fresh the house is in the market, the freshness of surrounding houses, and the phase of the market cycle. New listings have the strongest shopping externality effect on neighboring houses that have been on the market for some time. Vacant houses have their strongest competition effects in the declining market and externality effects in the rising market. Fresh houses on the market reap little benefit from shopping externalities in all phases of the market cycle.     

Analysing job creation effects of scaling up infrastructure spending in South Africa

In a first for South Africa, this article draws on literature on infrastructure productivity to model dynamic economy-wide employment impacts of infrastructure investment funded with different fiscal tools. Using a dynamic computable general equilibrium model, the South African investment plan is modelled, given the infrastructure externality. Alternative fiscal scenarios to finance the policy are modelled in the article. In the long run, unemployment decreases for all types of workers under one of the scenarios. In the short run, only elementary occupation workers benefit from a decrease in unemployment; for the rest, unemployment rises.     

Firm heterogeneity, productivity and spatially bounded knowledge externalities

In this paper, we argue that conceptually disentangling the ‘context versus composition’ aspects of regional growth is a multilevel issue. By applying multilevel models (also called random-effects models), we show (1) the importance of considering firm-specific characteristics simultaneously with region-specific characteristics, as we find that a large part of what is traditionally assigned to the impact of the region should be assigned to firm-specific characteristics and (2) that existing single-level methodologies can be problematic, as they are vulnerable to the charge of estimating significance levels that are too liberally assigned and promote exaggerations. This is illustrated empirically by showing that single-level approaches would lead to the conclusion that innovation spillovers are highly significant in a setting of Dutch urban growth differentials, while multilevel analyses shows less liberally assigned significance levels. We conclude that multilevel-effect models better fit research questions that combine firm and spatial characteristics simultaneously, especially because they allow firm-specific characteristics to be differently linked to their regional contexts.     

Bargaining externalities in a privatization programme

In privatization programmes, the state commonly keeps a minority ownership stake in firms. We provide an explanation based on the externality that privatization of one firm has on the profitability of others. If this externality is negative, as with oligopolistic firms, the government can gain a strategic advantage in bargaining over the sale of one firm if it keeps an ownership share in another. We consider both the simultaneous and the sequential sale of firms. The results apply to the period in which privatization takes place, and are consistent with the delayed sale of minority ownership often observed in practice.     

Jean Tirole,Nobel Prize Winner

The Royal Swedish Academy of Sciences awarded the Nobel Prize in Economic Sciences for 2014 to Jean Tirole, Toulouse School of Economics (TSE), Toulouse, France ‘for his analysis of market power and regulation’. What commonly characterizes Jean Tirole's work is a combination of rigorous scientific analysis of markets and provision of useful scientific insights and policy guidance for regulation and competition policy in such markets. This paper focuses on two of Tirole's papers, both co-written with Jean-Charles Rochet, which probably best exemplify his policy-oriented research. It summarizes and then explains how the theory that these papers develop led to the implementation of a new policy regulating the payment card industry in the European Union.     

Cost-sharing in directed networks: Experimental study of equilibrium choice and system dynamics

This study reports the results of an experiment on directed networks with positive externalities induced by cost-sharing. Subjects participated in a network game in which they had to choose between private and public transportations. If a player chose public transportation, then she shared the travel cost equally with other players making the same choice, whereas if she chose private transportation, then her travel cost was fixed. Travel costs on the private route were manipulated across the two experimental conditions. In one condition, these costs were homogeneous among players; in the other condition, they were heterogeneous among players and only privately known. We found that half (none) of the player groups in the homogeneous (heterogeneous) condition converged toward the efficient equilibrium. Examination of the system dynamics shows that convergence toward efficiency was facilitated by: (1) the existence of an intermediate equilibrium choice; and (2) strategic teaching by which a farsighted player chooses strategies with poor short-term payoff in order to shift group decisions to the efficient equilibrium and thereby increase her own long-term benefit.     

The effects of public spending externalities

We conduct a positive analysis on the effects of ‘externalities’ produced by government spending. To this effect, we estimate, using U.S. data, an RBC model with two salient features. First, we allow government consumption to directly affect the marginal utility of consumption. Second, we allow public capital to shift the productivity of private factors. We provide an identification analysis that supports the strategy adopted for estimating the parameters governing these two channels. On one hand, private and government consumption are robustly estimated to be substitute goods. Because of substitutability, labor supply reacts little to a government consumption shock, so the estimated output multiplier is much lower than in models with separabilities. On the other hand, our results point towards public investment being ‘unproductive’.     

上海市交通拥堵成本测算及对策研究

依据美国德克萨斯运输学院交通拥挤外部成本的经典测算模型，将交通运输拥挤成本分为时间延误成本、额外燃油消耗成本、环境污染物排放成本和噪音成本三个方面，对于2015年上海市工作日高峰期交通拥挤的外部成本进行了详细的测算。结果表明，交通拥堵的外部成本约占当年上海市GDP的0.63%。最后，对于交通拥堵成本较高的现状提出了包括对上海市部分高度拥堵路段或区域收取拥堵费、大力发展上海市公共交通和发展交通快慢型出行方式共存在内的相关政策和建议。     

对大企业外部性问题的研究

在带来巨大经济效益和高速经济增长的同时,大企业的外部性问题因其大规模生产和消费对整个社会和自然环境造成了严重的负面影响。同时对外部性问题的监测手段和技术的不断提升,以及社会大众对外部性问题的强烈关注,迫使大企业在政府监管督促的基础上,应该发挥其主观能动性,积极将其外部性问题内化。     

国防支出对经济增长的外部性效应及规模效应的分析

本文采用两部门外部性模型,研究中国国防开支对经济增长的外部性效应及规模效应,利用1978-2008年时间序列数据进行了实证分析,并且与学术界1960-2000年的研究结果做了对比。1978-2008期间的实证研究结果表明:规模效应为负,外部性效应为正。