Leonid Hurwicz, 90, became the oldest recipient of a Nobel Prize. Hurwicz, professor emeritus of the University of Minnesota, will share the Nobel Memorial Prize in Economic Science with economists Roger Myerson, a professor at the University of Chicago, and Eric Maskin, a professor at the Institute for Advanced Study in Princeton, N.J., both 56. They were awarded Monday for their work in mechanism design theory, a field initiated by Hurwicz and developed further by his co-honorees. Hurwicz was born in Russia and grew up in Poland, where his parents fled after the outbreak of World War I. He was studying in Geneva when World War II broke out and was forced to move to Portugual. His parents and brother were interned in Soviet labor camps. The three economists will share the $1.56 million prize money.