Joshua C. C. Chan, "Replication of the Results in 'Learning about
Heterogeneity in Returns to Schooling'", Journal of Applied Econometrics,
Vol. 20. No. 3, 2005, pp. 439-443.

This paper uses data from

Gary Koop and Justin L. Tobias, "Learning about Heterogeneity in Returns
to Schooling", Journal of Applied Econometrics, Vol. 19, No. 7, 2004,
pp. 827-849.

The data are available elsewhere in the JAE Data Archive. The URL is

  http://www.econ.queensu.ca/jae/2004-v19.7/koop-tobias/