Volume 8, Issue 1

We study the effect of privately informed traders on measured high frequency price changes and trades in asset markets. We use a standard market microstructure framework where exogenous news is captured by signals that informed agents receive. We show that the entry and exit of informed traders following the arrival of news accounts for high-frequency serial correlation in squared price changes (stochastic volatility) and trades. Because the bid-ask spread of the market specialist tends to shrink as individuals trade and reveal their information, the model also accounts for the empirical observation that high-frequency serial correlation is more pronounced in trades than in squared price changes. A calibration test of the model shows that the features of the market microstructure, without serially correlated news, accounts qualitatively for the serial correlation in the data, but predicts less persistence than is present in the data.

We show that the use of prior information derived from former empirical findings and/or subject matter theory regarding the lag structure of the observable variables together with an AR process for the error terms can produce univariate and single equation models that are intuitively appealing, simple to implement and work well in practice.

This paper considers the measurement of the equity risk premium in financial markets from a new perspective that picks up on a suggestion from Merton (1980) to use implied volatility of options on a market portfolio as a direct ‘ex-ante’ estimate for market variance, and hence the risk premium. Here the time variation of the unobserved risk premium is modelled by a system of stochastic differential equations connected by arbitrage arguments between the spot equity market, the index futures and options on index futures. We motivate and analyse a mean-reverting form for the dynamics of the risk premium. Since the risk premium is not directly observable, information about its time varying conditional distribution is extracted using an unobserved component state space formulation of the system and Kalman filtering methodology. In order to cater for the time variation of volatility we use the option implied volatility in the dynamic equations for the index and its derivatives. This quantity is in a sense treated as a signal that impounds the market’s ‘ex-ante’, forward looking, view on the equity risk premium. The results using monthly U.S. market data over the period January 1995 to June 2003 are presented and the model fit is found to be statistically significant using a number of measures. Comparisons with ex-post returns indicate that such historical measures may be understating the market risk premium.

Using a new methodology that allows nonlinearities, we find frequent support for external debt sustainability in a number of Latin American countries. Our findings reverse the results for several countries, obtained with traditional unit-root tests and present a richer framework for evaluating the external solvency of an economy. Our results also provide some justification for the assumption the international current accounts are based on.

Farmer (1991) suggests that in a model in which there are multiple rational expectations (RE) equilibria agents may find it useful to coordinate their expectations in a unique RE equilibrium which is immune to the Lucas Critique. In this paper, we evaluate Lucas proof (LP) equilibrium performance in the context of the term structure of interest rates model by using post-war US data. Estimation results show that LP equilibrium exhibits some important features of the data that are not reproduced by the fundamental equilibrium. For instance, the short rate behaves as a random walk in a regime characterized by low conditional volatility, whereas the term spread Granger-causes changes in the short-rate in periods characterized by high conditional volatility.