具有破裂风险的讨价还价模型研究

Rubinstein和Muthoo所建立的具有破裂风险的讨价还价模型,是基于将参与人对自身退出谈判的主观概率等价于参与人对谈判破裂风险的主观概率这一假设的基础之上的,但该假设却存在着缺陷。通过对讨价还价破裂风险内在机理的分析可以看出,参与人对谈判对手退出谈判的主观概率才是参与人对谈判破裂风险的主观概率。根据此结论修正后的模型,在本质上反映了参与人的均衡支付与其对谈判破裂风险的主观概率之间的关系,以及参与人的均衡支付与市场竞争之间的关系。     

Informational Efficiency and Information Subsets

This paper proposes a new definition of the Efficient Markets Hypothesis with respect to information, which is more formal and precise than those of Rubinstein 13 , Fama 4 , Jensen 6 , and Beaver 1 , and which fits well as a framework for interpreting the many tests of the Efficient Markets Hypothesis in the literature. Security markets are here considered “efficient with respect to information set ?” if and only if revealing ? to all agents would change neither equilibrium prices nor portfolios. In addition to other desirable features, this definition has the “subset property”: efficiency with respect to ? implies efficiency with respect to any subset of ?.     

Marketmaking Middlemen

This article develops a model in which market structure is determined endogenously by the choice of intermediation mode. There are two representative modes of intermediation that are widely used in real-life markets: one is a middleman mode where an intermediary purchases inventory from the wholesale market and resells to buyers; the other is a market-making mode where an intermediary offers a platform for buyers and sellers to meet and trade. We show that a marketmaking middleman, who adopts a mixture of these two intermediation modes, can emerge in a directed search equilibrium and discuss implications for the market structure.     

Differentiated networks: equilibrium and efficiency

We consider a model of price competition in a duopoly with product differentiation and network effects. In the efficient allocation, both networks are active and the firm with the highest expected quality has the largest market share. To characterize the equilibrium allocation, we derive necessary and sufficient conditions for uniqueness of the equilibrium of the coordination game played by consumers for given prices. The equilibrium allocation differs from the efficient one for two reasons. First, the equilibrium allocation of consumers to the networks is too balanced, because consumers fail to internalize network externalities. Second, if access to the networks is priced by strategic firms, then the product with the highest expected quality is also the most expensive. This further reduces the asymmetry between market shares and therefore social welfare.     

A model of unconventional monetary policy

We develop a quantitative monetary DSGE model with financial intermediaries that face endogenously determined balance sheet constraints. We then use the model to evaluate the effects of the central bank using unconventional monetary policy to combat a simulated financial crisis. We interpret unconventional monetary policy as expanding central bank credit intermediation to offset a disruption of private financial intermediation. Within our framework the central bank is less efficient than private intermediaries at making loans but it has the advantage of being able to elastically obtain funds by issuing riskless government debt. Unlike private intermediaries, it is not balance sheet constrained. During a crisis, the balance sheet constraints on private intermediaries tighten, raising the net benefits from central bank intermediation. These benefits may be substantial even if the zero lower bound constraint on the nominal interest rate is not binding. In the event this constraint is binding, though, these net benefits may be significantly enhanced.     

Inefficient liquidity creation

We present a model in which intermediaries create liquidity by issuing safe debt. Two types of intermediaries emerge: Traditional banks that create liquidity by issuing equity and holding assets to maturity, and market-based intermediaries that create liquidity by selling assets in fire sales in downturns. We show that the reliance on market-based intermediation is necessarily too high, but liquidity creation is not. It can also be too low as the endogenous fire-sale risk can push liquidity creation below its optimum. We argue that standard capital or liquidity regulation are ineffective, and optimal macroprudential regulation should instead target market-based intermediation.     

On the Positive Role of Financial Intermediation in Allocation of Venture Capital in a Market with Imperfect Information

This paper develops a theory of financial intermediation that highlights the contribution of intermediaries as informed agents in a market with imperfect information. We consider a venture capital market where the entrepreneurs select the qualities of projects and their perquisite consumptions, about which the investors are imperfectly informed. It is shown that when all investors have positive search costs, the entrepreneurs are induced to offer the unacceptable inferior projects (“lemons” only), and the investors will not enter the venture capital market, but put their funds in other low return investments–an undesirable allocation of resources. Beginning with an initial undesirable situation, the financial intermediaries may evolve as informed agents that induce a Pareto-preferred allocation, leading the investors to a higher welfare state. We focus our analysis on the existence of intermediation equilibra when the market for intermediation services is competitive. The distribution of returns on projects, the fees charged by intermediaries, and the fraction of institutional holdings are all endogenous in equilibrium. It is shown that (i) there cannot be a competitive intermediation equilibrium with very high institutional holdings, and (ii) in other cases multiple equilibra may exist, but the one with the highest institutional holdings dominates the others in a Pareto sense.     

The Economic Functions of Referrals and Referral Fees

As the real estate market becomes more complex, the role of middlemen becomes more central to its efficient operation. Middlemen take on informational roles including marketing, screening, and matching. The real costs incurred in many of these roles are not included in the regulatory authorities' calculations of permitted costs, and become, under RESPA, prohibited as referral fees. This discourages development of innovative packages of products. Regulation specifying the standards for disclosure of referral fees can serve a useful purpose. But the model in this article shows that in at least some circumstances customers will prefer to do business in an environment in which middlemen can choose not to reveal information about any particular referral fee they receive.     

The difference a day makes: Timely disclosure and trading efficiency in the muni market

The Real-Time Transaction Reporting System (RTRS) reduced the delay in reporting municipal bond trades from one-day to 15 min. We find a significant reduction in secondary market trading costs after the introduction of the RTRS. Our estimates imply that retail investors benefited primarily from reduced dealer intermediation costs, while large trades benefited from reductions in bargaining costs. Bonds experienced increases in trading volume across the liquidity spectrum. We find higher dealer capital commitment, longer intermediation chains, and fewer pre-arranged trades, all suggesting increased market-making incentives for dealers. These results are largely consistent with predictions from search-based models.     

Monetary Equilibrium and the Cost of Banking Activity

We investigate the effects of banks' operating costs on allocations and welfare in a low interest rate environment. We introduce an explicit production function for banks in a microfounded model where banks employ labor resources, hired on a competitive market, to run their operations. In equilibrium, this generates a spread between interest rates on loans and deposits, which reflects the underlying monetary policy and the efficiency of financial intermediation. In a deflation or low-inflation environment, equilibrium deposits yield zero returns. Hence, banks soak up labor resources to offer deposits that do not outperform idle balances, thus reducing aggregate efficiency.     

The Nash bargaining solution vs. equilibrium in a reinsurance syndicate

We compare the Nash bargaining solution in a reinsurance syndicate to the competitive equilibrium allocation, focusing on uncertainty and risk aversion. Restricting attention to proportional reinsurance treaties, we find that, although these solution concepts are very different, one may just appear as a first order Taylor series approximation of the other, in certain cases. This may be good news for the Nash solution, or for the equilibrium allocation, all depending upon one's point of view.

Our model also allows us to readily identify some properties of the equilibrium allocation not be shared by the bargaining solution, and vice versa, related to both risk aversions and correlations.     

Credit market frictions and the allocation of resources over the business cycle

In a seminal paper, Davis and Haltiwanger (1990) demonstrated that recessions are associated with increased job reallocation. The conventional view has interpreted this as evidence of “cleansing”: less productive jobs are destroyed in recessions, and resources are reallocated to more productive uses. This paper argues instead that in the presence of credit market frictions, reallocation might go the other way, directing resources from more efficient to less efficient uses. This will occur if more efficient production arrangements are also more vulnerable to credit constraints. I show that this pattern arises endogenously in an equilibrium model, and offer some evidence that firms with higher output per worker tend to borrow more, suggesting they are more vulnerable to credit constrains.     

PPP模式中公私双方努力水平与收益分配均衡决策研究

收益分配作为PPP模式中的一个关键决策对项目的成功运行具有重要影响。本文引入Stackelberg博弈模型，分别讨论和比较在集中决策与分散决策下的参与者最优努力水平和最佳收益分配方案，并进一步采用Rubinstein讨价还价博弈模型探究集中式决策下的利润分配。研究发现集中式决策下的努力水平和项目整体利益相对于分散式决策下的努力水平和项目整体利益都有所提高，并且通过对集中式决策下PPP项目的总体利润的合理分配可以实现帕累托改进。     

Labor tax reform, unemployment, and search

A key obstacle to reducing payroll taxes in many industrialized and transition countries is the direct revenue loss to the government that it implies. This paper studies a simple and practical labor tax reform of reducing a payroll tax and increasing a progressive wage tax that keeps the marginal tax wedge unchanged. Such a strategy increases employment, reduces the equilibrium unemployment rate, and increases public revenue as long as workers do not have all the bargaining power in wage negotiations. Moreover, welfare rises if workers’ bargaining power is sufficiently large to exceed a critical value determined by the second-best Hosios condition.      

A multisectorial matching model of unions

We develop an equilibrium matching model where unions have an important institutional presence. Monopolistic competition characterizes the goods market, where only some sectors are unionized. Thus, the model can vary the coverage of collective bargaining. It can vary the degree of coordination between unions, and alternatively consider “national” and “sectorial” unions. Calibration to the union premium implies a workers’ rent extraction parameter much lower than assumed in the matching literature. We introduce unemployment insurance to study the interactions of policies with unions and find that unions only push for more generous benefits if this does not entail higher payroll taxes.     

Optimal taxation and redistribution in an OLG model with unemployment

This paper concerns redistribution via nonlinear income taxation in an overlapping generations model with two ability-types. We assume that the wage rates are determined by bargaining between unions and firms, meaning that the equilibrium is characterized by involuntary unemployment. We show that the policy instruments that are used to calculate the marginal labor income tax rate for each ability-type give rise to intertemporal tax base effects. In addition, since the relationship between the employment and the capital stock implies intertemporal production inefficiency at the second best optimum, imperfect competition in the labor market may itself justify capital income taxation.      

Banks,financial markets,and social welfare

This paper constructs a general equilibrium model of banking and financial markets. The model allows to compare financial systems in which banks have access to financial markets with financial systems in which banks do not have access to financial markets. Allen and Gale [A welfare comparison of intermediaries and financial markets in Germany and the US. European Economic Review 39 (1995) 179–209] find that the Anglo-Saxon model of financial intermediation in which financial markets play a dominant role does not necessarily improve social welfare in comparison with the German model in which banks dominate. Our model provides a theoretical foundation for this view.     

Durable goods and conformity

A consumer's demand for a durable good is governed not only by his individual preferences but also by preferences of other market participants. This interdependence of preferences arises from the inevitable resale of durable goods. If most people prefer goods with certain features, original buyers conform and choose goods with these features even if they do not like them. Using a matching model, we show there is always conformity in equilibrium. The incentive to conform is strongest for long‐lived durables and for people who trade frequently. If average preferences are sufficiently strong, there is always too little conformity in equilibrium.     

Economic Impacts of the Possible China–US Trade War

This article uses a multi-country global general equilibrium (GE) model to numerically simulate the effects of possible China–US trade wars. We introduce an endogenous trade imbalance structure with trade cost into the model which helps to explore both tariff and non-tariff trade war effects. Our simulation results show that China will be significantly hurt by the China–US trade war, but negative impacts are affordable. The US can gain under unilateral sanction measures to China, but will lose if China takes retaliation measures. Comparing the effects under mutual trade war, China will lose more than the US. Introducing non-tariff barrier trade wars will intensify the negative effects, and comparatively negative effects to China are larger than to the US. Mexico’s involvement in trade war with the US will strengthen the negative effects and comparatively hurt the US more. Under non-cooperative and cooperative Nash bargaining equilibrium, the US can gain more than China in trade war negotiation, which means the US has stronger bargaining power than China. Additionally, trade wars between China and the US will hurt most countries and the world especially in GDP and manufacturing employment, but benefit their welfare and trade.     

Auctions versus negotiations: the effects of inefficient renegotiation

For the procurement of complex goods, the early exchange of information is important to avoid costly renegotiation. If the buyer can specify the main characteristics of possible design improvements in a complete contingent contract, scoring auctions implement the efficient allocation. If this is not feasible, the buyer must choose between a price‐only auction (discouraging early information exchange) and bilateral negotiations with a preselected seller (reducing competition). Bilateral negotiations are superior if potential design improvements are important, if renegotiation is very costly, and if the buyer's bargaining position is strong. Moreover, negotiations provide stronger incentives for sellers to investigate design improvements.