The computer revolution of the 1960s ushered in a golden period of econometric model building. Lawrence Klein was constantly in the forefront of this development. He was awarded the Alfred Nobel Memorial Prize in Economics for this and other contributions to applied econometrics.The 20th century witnessed a great expansion of economics as a scholarly discipline. The editor has chosen a selection of papers which sparked his interest as a student, a teacher and a researcher. This key volume includes both classic articles as well as lesser known papers which Professor Klein judges will stand the test of time.