A neglected nation gets its Nobel.
So who is this economist that the Wall Street Journal thinks is on its side? Well, economists do change their styles and their views as they get older; Mundell changed more than most. Those seminal early papers were crisp and minimalist; they looked forward with remarkable prescience to the wild and woolly, out-of-control world of modern international macroeconomics. By contrast, Mundell's writings since the early '70s have been discursive, one might almost say rambling, and often reveal a sort of hankering for the lost certainties of the gold standard. (And yes, he has said a few things that can, with some effort, be construed as support for supply-side economics.) The precocious theorist anticipated the 1990s; the elder statesman has hearkened back to the 1890s.
So you can take your pick as to which Mundell you prefer; but the Nobel committee basically honored Mundell the younger, the economist who was iconoclastic enough to imagine that Canada, of all places, was the economy of the future--and was right.
Paul Krugman writes a twice-weekly column for the New York Times and is professor of economics and international affairs at Princeton University. His home page contains links to many of his other articles and essays.