1992 Remembering. Mosaic (fall).

1994 Productivity, R&D and the data constraint. Am. Econ. Rev. 84 (1):1–23.

1996 The discovery of the residual: A historical note. J. Econ. Lit. 34 (3):1324–30.

1998 R & D and Productivity: The Econometric Evidence. Chicago: University of Chicago Press.

Practicing Econometrics: Essays in Method and Application. Northampton, Mass.: Edward Elgar.

2000 With T.J.Klette. Empirical patterns of firm growth and R&D investment: A quality ladder model interpretation. Econ. J. 110:363–87.