This article uses Projection Pursuit methods to develop a procedure for detecting outliers in a multivariate time series. We show that testing for outliers in some projection directions could be more powerful than testing the multivariate series directly. The optimal directions for detecting...

In this paper we consider the problem of designing a GI/M/c queueing system. Given arrival and service data, our objective is to choose the optimal number of servers so as to minimize an expected cost function which depends on quantities, such as the number of customers in the queue. A...

The problem of approximating an “image” S in R^d from a random sample of points is considered. If S is included in a grid of square bins, a plausible estimator of S is defined as the union of the “marked” bins (those containing a sample point). We obtain convergence rates for this...

In this paper we develop flexible techniques for measuring the speed of output convergence between countries when such convergence may be of an unknown non-linear form. We then calculate these convergence speeds for various countries, in terms of half-lives, from two time-series data-sets. These...

Many ways exist to measure and model financial asset volatility. In principle, as the frequency of the data increases, the quality of forecasts should improve. Yet, there is no consensus about a "true" or "best" measure of volatility. In this paper we propose to jointly consider absolute daily...

A new method, called relevant transformation of the inputs network approach (RETINA) is proposed as a tool for model building and selection. It is designed to improve on some of the shortcomings of neural networks. RETINA has the flexibility of neural network models, the concavity of the...

This paper contributes new evidence relating to the hypothesis that there has been convergence between certain male and female offences over time. Using time-series data for adults charged with offences in Canada over the period 1983 to 2000, we conduct several formal econometric tests of the...

There is now an extensive empirical literature relating to tests for various forms of convergence between the real per capita outputs of different countries. The evidence from these tests is mixed, and depends upon the type of data used, the countries in question, and the sample period in...

This paper examines the very long-run relationship between income and emissions of enteric methane in New Zealand, over the period 1895 to 1996. Controlling the emissions of this particular greenhouse gas is of crucial importance if that country is to meet its obligations as a signatory to the...

In the now extensive literature on the convergence of per capita income (output) across countries over time, there is surprisingly little attention paid to the role of international trade in goods and services. Some more recent studies have illustrated that standard trade theories provide no...