Optimal asset taxes in financial markets with aggregate uncertainty

This paper studies Pareto-optimal risk-sharing arrangements in a private information economy with aggregate uncertainty and ex ante heterogeneous agents. I show how to implement Pareto optima as equilibria when agents can trade claims to consumption contingent on aggregate shocks in financial markets. The first result is that if aggregate and idiosyncratic shocks are independent, the implementation of optimal allocations does not require any interventions in financial markets. This result can be extended to dynamic settings in the sense that, in this case, only savings need to be distorted, but not trades in financial markets. Second, I characterize optimal trading distortions in financial markets when aggregate and idiosyncratic shocks are not independent. In this case, optimal asset taxes must be higher for those securities that pay out in aggregate states in which consumption is more volatile. For instance, this can provide an efficiency justification for the frequently observed differential tax treatment of different asset classes, such as debt and equity claims.     

The set of sunspot equilibria in economies with incomplete financial markets: variable asset prices

Summary. I consider the set of equilibria of two-period economies with S extrinsic states of nature in the second period and I assets with linearly independent nominal payoffs. Asset prices are variable. If the number of agents is greater than (S-I), the payoff matrix is in general position and S 2I, the set of equilibrium allocations generically (in utility function space) contains a smooth manifold of dimension (S-1). Moreover, the map from states o f nature to equilibrium allocations (restricted to this manifold) is one-to-one at each equilibrium. Received: February 23, 1998; revised version: June 1, 2000     

Liquidity risk and financial competition: Implications for asset prices and monetary policy

This paper studies the implications of banking competition for capital markets and monetary policy. In particular, I develop a two-sector monetary growth model in which a group of agents is exposed to liquidity shocks and money is essential. Banks insure depositors against such risk and invest in the economy's assets. In this setting, I compare an economy with a perfectly competitive banking sector to an economy with a fully concentrated financial sector. Unlike previous work, banks can have market power in both deposits and capital markets. Compared to a perfectly competitive financial sector, I demonstrate that a monopolistic banking system can have substantial adverse consequences on capital formation, assets prices, and the degree of risk sharing. Furthermore, multiple steady-states can emerge and the economy becomes subject to poverty traps. More importantly, market power in financial markets may overturn the Tobin effect present under a perfectly competitive financial sector. This necessarily happens in economies with high degrees of liquidity risk and low levels of capital formation.     

The role of financial sector competition for monetary policy

Abstract In this paper, we examine the impact of competition in the banking industry on financial market activity. In particular, we explore this issue in a setting where banks simultaneously insure individuals against liquidity risk and offer loans to promote intertemporal consumption smoothing. In addition, spatial separation and private information generate a transactions role for money. Interestingly, we demonstrate that the industrial organization of the financial system bears significant implications for the effects of monetary policy. Under perfect competition, higher rates of money growth lead to lower interest rates and a higher volume of lending activity. In contrast, in a monopoly banking sector, money growth restricts the availability of funds and raises the cost of borrowing.     

The role of labor markets for euro area monetary policy

In this paper, we explore the role of labor markets for monetary policy in the euro area in a New Keynesian model in which labor markets are characterized by search and matching frictions. We first investigate to which extent a more flexible labor market would alter the business cycle behavior and the transmission of monetary policy. We find that while a lower degree of wage rigidity makes monetary policy more effective, i.e. a monetary policy shock transmits faster onto inflation, the importance of other labor market rigidities for the transmission of shocks is rather limited. Second, having estimated the model by Bayesian techniques we analyze to which extent labor market shocks, such as disturbances in the vacancy posting process, shocks to the separation rate and variations in bargaining power are important determinants of business cycle fluctuations. Our results point primarily towards disturbances in the bargaining process as a significant contributor to inflation and output fluctuations. In sum, the paper supports current central bank practice which appears to put considerable effort into monitoring euro area wage dynamics and which appears to treat some of the other labor market information as less important for monetary policy.     

The continuous time random walk formalism in financial markets

We adapt continuous time random walk (CTRW) formalism to describe asset price evolution and discuss some of the problems that can be treated using this approach. We basically focus on two aspects: (i) the derivation of the price distribution from high-frequency data, and (ii) the inverse problem, obtaining information on the market microstructure as reflected by high-frequency data knowing only the daily volatility. We apply the formalism to financial data to show that the CTRW offers alternative tools to deal with several complex issues of financial markets.     

The future of financial markets: financial crisis avoidance

This article considers the lessons from the global financial crisis for redesigning the financial system and its regulation to make the chance of future such crises lower. It focuses on three areas: improvements to the regulation of individual financial firms; macroprudential analysis and improving the structure of crisis resolution and management. It argues that if the authorities implement a credible crisis management regime where no firm is too big to be resolved, a smarter and more incentive based approach to the regulation of individual financial firms and extensive macroprudential analysis that both makes the structure of financial markets less risky and identifies risks, the risk of future crises will be reduced. But no framework can eliminate the risk altogether.     

Information from financial markets and VAR measures of monetary policy

Exogenous measures of monetary policy shocks, directly derived from financial market information, are used in close (US) and open (US–Germany) economy VAR models to evaluate the robustness of the dynamic effect of monetary policy obtained from traditional identified VAR. The empirical analysis confirms the main features of the monetary policy transmission mechanism in US and Germany, explicitly addressing the issue of simultaneity between the German policy interest rate and the US dollar–DMark exchange rate.     

The structure of the set of sunspot equilibria in economies with incomplete financial markets

Summary This paper considers the set of equilibria of two-period, sunspot economies withS purely extrinsic states of nature in the second period andI assets with linearly independent nominal payoffs. The span of the payoff matrix contains the vector [1, ... , 1] (i.e., inside money). The set of economies is described in terms of (sunspot-invariant) utility functions. IfS>I> 0, there is an open, dense set of economies such that, given a vector of no arbitrage asset prices, the set of equilibrium allocations contains a smooth manifold of dimensionS—I. Such a manifold contains at least one nonsunspot equilibrium (and at most a finite number of such equilibria).The paper was written while I was a visitor at C.O.R.E., Universitè Catholique de Louvain, with the financial support of a S.P.E.S. fellowship. I would like to thank D. Cass, H. Polemarchakis and P. Siconolfi for their helpful comments.     

Transactions technology and the time consistency of optimal policy

In a perfect foresight, continuous time model of the macro economy. Turnovsky and Brock (1980) have demonstrated that the government's choice of an optimal policy will be time inconsistent only if it is bound by a k% rule regarding the growth of nominal monetary balances. This result is shown to be invalid when bonds bear a liquidity yield. Under such circumstances, it is shown that all optimal policies are time inconsistent. The conclusion is that the liquidity properties of the government's financing instruments play an important role in determining the consistency properties of its optimal policies.     

Economic policy uncertainty,financial markets and probability of US recessions

We use probit recession forecasting models to assess the ability of economic policy uncertainty indexes developed by Baker et al. (2013) to predict future US recessions. The model specifications include policy indexes on their own, and in combination with financial variables, such as interest rate spreads, stock returns and stock market volatility. Both in-sample and out-of-sample analysis suggests that the policy uncertainty indexes are statistically and economically significant in forecasting recessions at the horizons beyond five quarters. The index based on newspaper reports emerges as the best predictor, outperforming the term spread at the longer forecast horizons.     

The revenue potential of a financial transaction tax for US financial markets

This paper estimates the revenue potential of a financial transaction tax (FTT) for US financial markets. We focus on analyzing the revenue potential of the Inclusive Prosperity Act that was introduced in the US House of Representatives in 2012 and the US Senate in 2015. The tax rates stipulated in this Act include 0.5% (50 basis points (bps)) for all stock transactions, 0.1% (10 bps) for all bond transactions and 0.005% (0.5 bps) on the notional value of all derivative trades. We examine three sets of evidence to generate potential revenue estimates: 1) the levels of transaction costs in US financial markets over time and within the range of financial market segments; 2) the extent of trading elasticities under various trading conditions; and 3) the current level of trading activity in US financial markets. Based on this evidence, we conclude that a US FTT operating at the tax rates stated above would generate about $220 billion per year, equal to about 1.2% of the current US GDP.     

International stock markets comovements: the role of economic and financial integration

The contribution of economic and financial integration to international stock markets comovements are investigated by means of a large scale macroeconometric model, set in the factor vector autoregressive framework (F-VAR). The findings point to a relevant role for both economic and financial integration in explaining international stock markets comovements for the G-7 countries. While economic integration would exercise its effects through the common response of stock markets to global economic shocks, financial integration would operate through financial shocks spillovers, particularly at the regional level.      

Aggregation of heterogenous beliefs,asset pricing,and risk sharing in complete financial markets

Given a competitive equilibrium in complete asset markets, we propose a method that aggregates heterogeneous individual beliefs into a single “market probability,” which, if commonly shared by investors, generates the same marginal valuation of assets by the market as well as by each individual investor. As a result of the aggregation process, the market portfolio may have to be scalarly adjusted, upward or downward, a reflection of an aggregation bias due to the diversity of beliefs. From a dual viewpoint, the standard construction of an expected utility-maximizing aggregate investor designed to represent the economy in equilibrium, is shown to be also valid in the case of heterogeneous beliefs, modulo the above scalar adjustment of the market portfolio, thereby generating an Adjusted version of the Consumption based Capital Asset Pricing Model (ACCAPM). We analyze how the allocation of aggregate and individual risks relates to deviations of individual beliefs from the aggregate market probability. Finally, we identify the channels through which the distribution of beliefs and other microeconomic characteristics (incomes, attitudes toward risk) across investors impact the pricing of risky assets an may contribute to explaining the equity premium puzzle.     

金融资产定价理论的历史回顾与展望

金融资产定价理论是金融学的核心问题，华尔街的两次“革命”都源自于对资产定价理论的研讨。通过对金融资产定价理论的历史文献回顾，可以把资产定价理论大致分为三个阶段：萌芽阶段、发展阶段和繁荣阶段。其中，萌芽阶段在20世纪50年代以前的时间段，发展阶段在20世纪50年代到70年代，繁荣阶段则在20世纪80年代以后到目前的时间段。最后对金融资产定价理论做出展望，指出现代数学方法的运用仍是资产定价理论向前发展的动力。     

Generic inefficiency of equilibria in the general equilibrium model with incomplete asset markets and infinite time

Summary. We consider a Lucas asset-pricing model with heterogeneous agents, exogenous labor income, and a finite number of exogenous shocks. Although agents are infinitely lived, endowments and dividends are time-invariant functions of the exogenous shock alone and are thus restricted to lie in a finite-dimensional space; genericity analysis can be conducted on sets of zero Lebesgue measure. When financial markets are incomplete, that is, there are fewer financial securities than shocks, we show that generically in individual endowments all competitive equilibria are Pareto inefficient. Received: November 22, 1999; revised version: March 4, 2002 RID="*" ID="*" We are grateful to an anonymous referee for very insightful comments on earlier drafts.     

The role of financial speculation in the energy future markets: A new time-varying coefficient approach

To study whether speculating behavior plays an important role in oil futures markets, this paper proposes a time-varying coefficient version of the model of Llorente, Michaely, Saar, and Wang (2002) and estimates the effect of the speculating behavior using a sieve maximum likelihood estimation method. Using the time-varying coefficient model and the data of crude oil and heating oil futures markets, we find that neither the speculative motive nor the hedging motive dominates the markets over the whole sample period. However, we find that one of the two motives dominates the markets over some subsample periods. More importantly, speculation dominates in both the crude oil and heating oil futures markets around 2008. These empirical findings support the argument that the speculating behavior significantly affected the sharp rise in the price of crude oil in 2008.     

Negative price spikes at power markets: the role of energy policy

In Germany, substantial drops in wholesale power prices have become a regular phenomenon. While such price drops have far-reaching implications for the functioning of the power market, their underlying determinants remain poorly understood. To fill this gap, we propose a Markov regime-switching model to investigate low-price events at the European Power Exchange. Our analysis focuses on the role of energy policies that promote renewable energies and have led to significant reductions of nuclear capacities after the Fukushima accident. We find that high electricity infeed from renewable sources increases negative price spike probabilities, while the decommissioning of nuclear plants under the Nuclear Moratorium had an opposing effect. Simulations of market outcomes under different energy policies indicate that reaching ambitious renewable energy targets increases the frequency of low-price events and compromises the financial viability of conventional generation units, while a nuclear phase-out or an increase in storage capacities mitigates these effects.