Stockholm: American Robert F Engle and Briton Clive W J Granger won the 2003 Nobel Memorial Prize in Economic Sciences for their use of statistical methods for economic time series, the Royal Swedish Academy of Sciences said on October 8.

The Academy said the research is used to gather data for time series, such as chronological observations or for estimating relationships and testing hypotheses in economic theory.

"Such time series show the development of (gross domestic product), prices, interest rates, stock prices, etc," the citation said.

Engle, 60, a native of Syracuse, New York, is on faculty at New York University and Granger, 69, a native of Swansea, Wales, is at the University of California at San Diego. He is the fourth consecutive American to receive the award since 2000.

Their findings are important because on financial markets, random fluctuations and volatility can affect share prices and value, along with other financial instruments.

Peter Englund, a banking and insurance professor at the Stockholm Institute for Financial Research, said the two men's research has helped economists and financial experts "measure and estimate volatility and how volatility varies over time. This has most of its applications in financial markets, for instance how the volatility of stock returns and investment returns in general vary over time, he said.

Agencies