Political Institutions and Policy Volatility

Checks and balances that limit the discretion of policy-makers reduce the volatility of government expenditure and revenue. While this assumption is at the heart of a large body of empirical work, the association between political institutions and policy volatility has itself been the focus of only limited empirical testing. The results presented here support the existence of this link, allow for a comparison between two prominent measures of checks and balances and provide insight into the relative impact of checks and balances on the volatility of nine different types of fiscal policy both during times of macroeconomic stability and upheaval.     

Sequential estimation of a location parameter and powers of a scale parameter from delayed observations

The problem of sequentially estimating a location parameter and powers of a scale parameter is considered in the case when the observations become available at random times. Certain classes of sequential estimation procedures are derived under an invariant balanced loss function and with the observation cost determined by a convex function of the stopping time and the number of observations up to that time.     

Employment fluctuations and dynamics of the aggregate average wage in Poland, 1996–20031

The aggregate average wage is often used as an indicator of economic performance and welfare, and as such often serves as a benchmark for changes in the generosity of public transfers and for wage negotiations. Yet if economies experience a high degree of (non‐random) fluctuation in employment, the composition of the employed population will have a considerable effect on the computed average. In this paper we demonstrate the extent of this problem using data for Poland for the period 1996–2003. During these years the employment rate in Poland fell from 51.2 percent to 44.2 percent and most of this fall occurred between the end of 1998 and the end of 2002. We show that about a quarter of the growth in the average wage during this period could be attributed purely to changes in employment.     

Generalized variance-ratio tests for serial correlation in multivariate regression models

Exact tests for rth order serial correlation in the multivariate linear regression model are devised which are based on a multivariate generalization of the F-distribution. The tests require the computation of two multivariate regressions. In the special case of a single-equation regression model the procedures reduce to simple always-conclusive F-tests. The tests are illustrated by applications to the Rotterdam Model of consumer demand.     

An invariance property of Farebrother's procedure for estimation with aggregated data

A procedure proposed by Farebrother (1979) for estimating the parameters of a standard Gauss-Markov model from aggregated data is shown to be invariant with respect to the choice of a generalized inverse of the matrix designated to approximate the unknown dispersion matrix of a transformed model, thus correcting Farebrother's statement that this desirable property cannot be attributed to his procedure.     

Forward rate models with linear volatilities

The existence of solutions to the Heath?CJarrow?CMorton equation of the bond market with linear volatility and general Lévy random factor is studied. Conditions for the existence and non-existence of solutions in the class of bounded fields are presented. For the existence of solutions, the Lévy process should necessarily be without a Gaussian part and without negative jumps. If this is the case, then necessary and sufficient conditions for the existence are formulated either in terms of the behavior of the Lévy measure of the noise near the origin or the behavior of the Laplace exponent of the noise at infinity.     

Applying free random variables to random matrix analysis of financial data. Part I: The Gaussian case

We apply the concept of free random variables to doubly correlated (Gaussian) Wishart random matrix models, appearing, for example, in a multivariate analysis of financial time series, and displaying both inter-asset cross-covariances and temporal auto-covariances. We give a comprehensive introduction to the rich financial reality behind such models. We explain in an elementary way the main techniques of free random variables calculus, with a view to promoting them in the quantitative finance community. We apply our findings to tackle several financially relevant problems, such as a universe of assets displaying exponentially decaying temporal covariances, or the exponentially weighted moving average, both with an arbitrary structure of cross-covariances.