NOBEL PRIZE: A Briton and an American yesterday shared the 2003 Nobel Prize for Economics, while two Americans won the Nobel Prize for Chemistry.
The US economist, Mr Robert Engle, and Britain's Mr Clive Granger shared the economics prize, the Royal Swedish Academy of Sciences announced.
"This year's laureates devised new statistical methods for dealing with two key properties of many economic time series: time-varying volatility and non-stationarity," the academy said in its citation for the 10 million crown (€1.1 million) prize.
Mr Engle, born in New York in 1942, teaches at New York University. "His . . . models have become indispensable tools not only for researchers but also for analysts on financial markets, who use them in asset pricing and in evaluating portfolio risk," the academy said.
Mr Granger, born in 1934 in Wales, is a professor of economics at the University of California. The academy said his work was used in studying "the relations between wealth and consumption, exchange rates and price levels, and short and long-term interest rates."
The prize for chemistry went to Mr Peter Agre and Mr Roderick MacKinnon for studies of tiny channels in cell membranes, which have contributed to the understanding of fundamental life processes. The citation said their discoveries of how salts and water are transported in and out of human cells was of "great importance for our understanding of many diseases".
"They have opened our eyes to a fantastic family of molecular machines: channels, gates and valves all of which are needed for the cell to function."
Mr Agre (54), from Northfield, Minnesota, works at the Johns Hopkins University School of Medicine in Baltimore. Mr MacKinnon (47) grew up near Boston and works at the Howard Hughes Medical Institute at New York's Rockefeller University.
"The discoveries have afforded us a fundamental molecular understanding of how, for example, the kidneys recover water from primary urine and how the electrical signals in our nerve cells are generated and propagated," the academy said.
In 1991, Mr Agre discovered a molecular membrane water channel. His finding ultimately revealed an entire family of water channels now called aquaporins.
"This decisive discovery opened the door to a whole series of biochemical, physiological and genetic studies of water channels," the citation said.
"Researchers can follow in detail a water molecule on its way through the cell membrane and understand why only water, not other small molecules or ions, can pass," it said, adding this had enhanced medical doctors' understanding of kidney diseases.
Mr MacKinnon's contribution was in the field of ion channels, which are membrane-spanning proteins that form a pathway for the flow of inorganic ions across cell membranes.