How can public pension systems be reformed to ensure fiscal stability in the face of increasing life expectancy?  To address this pressing open question in public finance, we estimate a life-cycle model in which the optimal employment, retirement and consumption decisions of forward-looking...

India's development experience over the past fifty years suggests that the increasing importance of the services sector deserves analysis.  The literature on structural change has emphasised changing patterns of demand as an explanation for the increasing importance of the services sector.  In...

I discuss models which allow the local level model, which rationalised exponentially weighted moving averages, to have a time-varying signal/noise ratio.  I call this a martingale component model.  This makes the rate of discounting of data local.  I show how to handle such models...

High frequency financial data allows us to learn more about volatility, volatility of volatility and jumps.  One of the key techniques developed in the literature in recent years has been bipower variation and its multipower extension, which estimates time-varying volatility robustly to...

We investigate the properties of the composite likelihood (CL) method for (T x NT) GARCH panels.  The defining feature of a GARCH panel with time series length T is that, while nuisance parameters are allowed to vary across NT series, other parameters of interest are assumed to be common.  CL...

Building models for high dimensional portfolios is important in risk management and asset allocation.  Here we propose a novel and fast way of estimating models of time-varying covariances that overcome an undiagnosed incidental parameter problem which has troubled existing methods when applied...

We propose a new measure of risk, based entirely on downward moves measured using high frequency data.  Realised semivariances are shown to have important predictive qualities for future market volatility.  The theory of these new measures is spelt out, drawing on some new results from...

In this paper we review the history and recent developments of stochastic volatility, which is the main way financial economists and mathematical finance specialists model time varying volatility.

We study the role of the propensity scores in estimating treatment effects for the treated with a multi-valued treatment.  Assume assignment to one of the multiple treatments is random given observed characteristics.  Valid causal comparisons for the subpopulation who has been treated a...