Information sharing among firms and cyber attacks

As the Sarbanes-Oxley Act strengthens internal controls, and the government encourages information sharing, accounting gains significance through secure representation, storage, and transfer of information, and by laying the foundation for assessing costs and benefits. Information sharing and security investment for two firms are inverse U shaped in the aggregate attack, and interlinked through the interdependence and the firm’s unit cost of security investment. Both increase in the interdependence (e.g. US telecommunications industry). With given security investment, social welfare is inverse U shaped in information sharing. Individual optimization implies free riding. A social planner is introduced controlling information sharing, security investment, or both, in simultaneous and two period games. Two period games where the social planner moves first are realistic when the social planner is highly respected. For the simultaneous game, a social planner controlling information sharing (security investment) imposes unreasonably high sharing (security investment). Firms free ride in the variable they control. The social planner imposes more moderate levels in the two period games. A social planner controlling both information sharing and security investment in a two period game where the social planner moves first is the most beneficial control scenario when the firms’ defense efficiencies are high. If these are sufficiently high, the attack is deterred altogether.     

Investment in concealable information by biased experts

We study a persuasion game in which biased—possibly opposed—experts strategically acquire costly information that they can then conceal or reveal. We show that information acquisition decisions are strategic substitutes when experts have linear preferences over a decision maker's beliefs. The logic turns on how each expert expects the decision maker's posterior to be affected by the presence of other experts should he not acquire information that would turn out to be favorable. The decision maker may prefer to solicit advice from just one biased expert even when others—including those biased in the opposite direction (singular)—are available.     

Inflation and Welfare in Retail Markets: Prior Production and Imperfectly Directed Search

This paper considers the effect of monetary policy and inflation on retail markets: goods are dated and produced prior to being retailed; buyers direct their search on price and general quality; buyers’ match‐specific tastes are private information. Sellers set the same price for all buyers, some of whom do not value the good highly enough to buy it. The market economy is typically inefficient as a social planner would have the good consumed. Under free entry of sellers, the Friedman rule is optimal policy. When the upper bound on the number of participating sellers binds, moderate levels of inflation can be welfare improving.     

Venture Capital and Capital Allocation

I show that venture capitalists' motivation to build reputation can have beneficial effects in the primary market, mitigating information frictions and helping firms go public. Because uninformed reputation‐motivated venture capitalists want to appear informed, they are biased against backing firms—by not backing firms, they avoid taking low‐value firms to market, which would ultimately reveal their lack of information. In equilibrium, reputation‐motivated venture capitalists back relatively few bad firms, creating a certification effect that mitigates information frictions. However, they also back relatively few good firms, and thus, reputation motivation decreases welfare when good firms are abundant or profitable.     

The optimal inheritance tax in the presence of investment in education

This paper provides an example aimed at calculating the optimal inheritance tax in a model in which inheritances are used to finance investment in education. Two results are obtained: (1) The optimal inheritance tax schedule includes a threshold, estimated between 2.5 and 5.5 times per-capita GDP. This result holds for a Rawlsian social planner that maximizes the welfare of the poorest individual, who does not leave bequests. (2) Contrary to the result of a 100 % tax on pure accidental bequests, the optimal simulated tax rates are between 28 %, for the case of educational bequests, and 57 %, for the case where educational and accidental bequests interact. This range is in line with existing schedules in developed economies.     

Optimal Financial Transaction Taxes

This paper characterizes the optimal transaction tax in an equilibrium model of financial markets. If investors hold heterogeneous beliefs unrelated to their fundamental trading motives and the planner calculates welfare using any single belief, a positive tax is optimal, regardless of the magnitude of fundamental trading. Under some conditions, the optimal tax is independent of the planner's belief. The optimal tax can be implemented by adjusting its value until total volume equals fundamental volume. Knowledge of (i) the share of nonfundamental trading volume and (ii) the semielasticity of trading volume to tax changes is sufficient to quantify the optimal tax.     

Market power,price discrimination,and allocative efficiency in intermediate‐goods markets

We consider a monopolistic supplier's optimal choice of two‐part tariff contracts when downstream firms are asymmetric. We find that the optimal discriminatory contracts amplify differences in downstream firms' competitiveness. Firms that are larger—either because they are more efficient or because they sell a superior product—obtain a lower wholesale price than their rivals. This increases allocative efficiency by favoring the more productive firms. In contrast, we show that a ban on price discrimination reduces allocative efficiency and can lead to higher wholesale prices for all firms. As a result, consumer surplus, industry profits, and welfare are lower.     

Endogenous market segmentation for lemons

Information asymmetry between sellers and buyers often prevents socially desirable trade. This article presents a new mechanism that mitigates the inefficiencies caused by information asymmetry. I consider decentralized markets under adverse selection and show that such markets can be endogenously segmented in a way that improves social welfare. Endogenous segmentation is driven by low‐quality sellers’ incentive to attract more buyers by separating from high‐quality sellers. The mechanism helps us understand the roles of several real‐world institutions, such as multiple marketplaces, costless advertisements, and nonbinding list prices.     

Procurement with specialized firms

We analyze optimal procurement mechanisms when firms are specialized. The procurement agency has incomplete information concerning the firms' cost functions and values high quality as well as low price. Lower type firms are cheaper (more expensive) than higher type firms when providing low (high) quality. With specialized firms, distortion is limited and a mass of types earns zero profits. The optimal mechanism can be inefficient: types providing lower second‐best welfare win against types providing higher second‐best welfare. As standard scoring rule auctions cannot always implement the optimal mechanism, we introduce a new auction format implementing the optimal mechanism.     

The roles of reputation and transparency on the behavior of biased experts

We analyze situations in which an expert is biased toward some decision but cares also about his reputation in the market for experts. The information the expert reveals decreases as his bias moves toward stronger preferences for the status quo. Surprisingly, revealing the intensity of the expert’s bias does not always improve the information he reveals in equilibrium. The presence of a second expert raises the first expert’s incentives to report truthfully when the market can identify the contribution of each expert, but reduces them when only the collective contribution is identified by the market.     

Optimal information revelation in procurement schemes

A buyer procuring a single input possesses private information about each potential supplier's degree of fit with the buyer's needs. She can search among suppliers either sequentially or simultaneously. As long as the distribution of the fit parameter is not overly skewed to the left, sharing information with suppliers yields intensified price competition under simultaneous search. Moreover, the buyer cannot benefit by providing suppliers additional information beyond their own fitness parameter. Information revelation is never optimal with sequential search.     

Sequential payments and optimal pricing in payment systems

This paper studies the intraday payment behaviour between heterogeneous banks as well as optimal intraday pricing schemes. The paper shows the social optimality of payment sequencing, which allows a bank to delay payments until the bank receives payments from the counterparty. The payment sequencing allows a bank with high liquidity cost to ‘recycle’ payment inflow from another bank with lower liqudity cost, reducing the aggregate cost of funding of banks to settle all payments. But we also see that the banks have an incentive to delay payments more than the payment sequencing requires. This underscores the importance of social planner’s role reducing settlement delay, while leaving socially efficient payment sequencing. In this context, we compare two different pricing schemes, a standard throughput guideline and a time-varying intraday tariff, to discuss the optimal incentive mechanisms in payment systems for the ‘socially efficient sequential settlement’.     

The Effect of Sequential Information Arrival on Asset Prices: An Experimental Study

A complete understanding of security markets requires a simultaneous explanation of price behavior, trading volume, portfolio composition (ie., asset allocation), and bid-ask spreads. In this paper, these variables are observed in a controlled setting—a computerized double auction market, similar to NASDAQ. Our laboratory allows experimental control of information arrival—whether simultaneously or sequentially received, and whether homogeneous or heterogeneous. We compare the price, volume, and share allocations of three market equilibrium models: telepathic rational expectations, which assumes that traders can read each others minds (strong-form market efficiency); ordinary rational expectations, which assumes traders can use (some) market price information, (a type of semi-strong form efficiency); and private information, where traders use no market information. We conclude 1) that stronger-form market models predict equilibrium prices better than weaker-form models, 2) that there were fewer misallocation forecasts in simultaneous information arrival (SIM) environments, 3) that trading volume was significantly higher in SIM environments, 4) and that bid-ask spreads widen significantly when traders are exposed to price uncertainty resulting from information heterogeneity.     

Credit Traps and Macroprudential Leverage

We construct a macroeconomic model with overlapping generations to study credit traps—prolonged periods of stagnant real activity accompanied by low productivity, financial sector undercapitalization, and credit misallocation. Shocks to bank capital tighten banks' borrowing constraints causing them to allocate credit to easily collateralizable but low productivity projects. Low productivity weakens bank capital generation, reinforcing tight borrowing constraints, sustaining the credit trap steady state. Macroprudential policy to limit bank leverage can be welfare enhancing. In the presence of a credit trap, optimal leverage policy is countercyclical.     

Games within borders: are geographically differentiated taxes optimal?

The discontinuous tax treatment of sales at borders creates incentives for individuals to cross-border shop. This paper addresses whether it is optimal for a state composed of multiple regions to levy differentiated commodity tax rates across the regions. In a model where states maximize social welfare, a state’s optimal commodity tax system is almost always geographically differentiated. The optimal pattern of geographic differentiation critically depends on fundamental parameters as well as whether the state has a preference for high or low taxes. Under the assumption that utility is linear in consumption and that the elasticity of cross-border shopping is less than unity in absolute value, high-tax states will find it optimal to set a tax rate that is lower in the border region than in the periphery region and low-tax states will find it optimal to set a tax rate that is higher in the border region than in the periphery region. Optimizing high-tax states will set a higher tax rate in the border region if the social welfare measure is sufficiently redistributive. With welfare maximization, it is possible for taxes to be higher in the region near the state border—an outcome that cannot arise when the government cares only about total tax revenue.     

Redistributive taxation and social insurance under adverse selection in the insurance market

This paper extends the analysis of optimal income taxation under uncertainty studied by Cremer and Pestieau (International Tax and Public Finance, 3, 281–295, 1996). We introduce asymmetric information in the insurance market whereby private insurance companies cannot identify the risk probability of the agents, and we examine its effect on public policy. We consider the separating equilibrium of Rothschild and Stiglitz (Quarterly Journal of Economics, 90, 629–649, 1976) and Riley (Econometrica, 47, 331–359, 1979) where the low risk agent is only partially insured. The presence of the distortion in the insurance market changes the affinity of labor, and in some cases, we show that the scope of redistribution and the resulting social welfare are higher under asymmetric information than under full information. We also show that the increase in social insurance affects the utility and labor incentive of the low risk type by relaxing the self-selection constraint in the insurance market. The policy implications of the redistributive taxation and social insurance are analytically and numerically examined.      

风险最优配置理论及其对完善我国社会保障制度的启示

风险的配置也存在着帕累托有效,即各类风险都落在最愿意承担该风险的主体上。无论公民个人,还是社会整体,都可以通过风险的合理配置,来增进自身的经济福利。事实上,将储蓄作为应对未来不确定性的主要手段,蕴含着风险配置的效率损失,因此,有必要建立一种能引导个人储蓄向社会保障资金转化的机制,以改善社会效率。     

Optimal taxation with home production

Optimal taxes for Europe and the U.S. are derived in a realistically calibrated model in which agents buy consumption goods and services and use home capital and labor to produce household services. The optimal tax rate on services is substantially lower than the tax rate on goods. Specifically, the planner cannot tax home production directly and instead lowers the tax rate on market services to increase the relative price of home production. The optimal tax rate on the return to home capital is strictly positive and the welfare gains from switching to optimal taxes are large.     

Adverse selection and moral hazard: Quantitative implications for unemployment insurance

A model of optimal unemployment insurance with adverse selection and moral hazard is constructed. The model generates both qualitative and quantitative implications for the optimal provision of unemployment insurance. Qualitatively, for some agents, incentives in the optimal contract imply consumption increases over the duration of non-employment. Calibrating the model to a stylized version of the U.S. economy quantitatively illustrates these theoretical predictions. The optimal contract achieves a welfare gain of 1.94% relative to the current U.S. system, an additional 0.87% of gains relative to a planner who ignores adverse selection and focuses only on moral hazard.     

The Welfare State in a Changing Environment

We analyse how the welfare state, i.e., social insurance that works through redistributive taxation, should respond to increases in risks and to increases in the cost of operating the welfare state. With respect to risks, we distinguish between risks that can be insured and such that cannot (background risks). Insurable risks can be reduced by costly individual self-insurance and by costly social insurance. We show: (i) Self-insurance will be higher the more costly is the welfare state and the larger are background or insured risks. (ii) Full social insurance can only be optimal in a costless welfare state. (iii) The optimal welfare state is not necessarily larger the less costly it is. (iv) The welfare state need not optimally expand when risks increase that it insures. (v) It should, however, expand when risks increase that it does not insure.