In 1974 Granger moved to the United States, to the University of California at San Diego. In 1975 he participated in a US Bureau of Census committee chaired by Arnold Zellner on seasonal adjustment. At UCSD, Granger continued his research on time series, collaborating closely with Nobel prize co-recipient Robert Engle (whom he helped bring to UCSD), Roselyne Joyeux (on fractional integration), Timo Teräsvirta (on nonlinear time series) and others. Working with Robert Engle, he developed the concept of cointegration, introduced in a 1987 joint paper in Econometrica; for which he was awarded the Nobel prize in 2003.