Introduction
Returns to investment in education, in the modern/human capital sense of the term,
have been estimated since the late 1950s. In the 40-plus year history of estimates of
returns to investment in education, there have been several reviews of the empirical
results in attempts to establish patterns (see Psacharopoulos, 1973, 1985, 1994).
The rise in earnings inequality experienced during the 1980s and 1990s in many
countries led to renewed interest in estimates of returns to schooling (see, for example,
Murphy & Welch, 1992). A very large literature suggests that systematic
changes in the production process led to changes in the demand for certain types of
labor. It was argued much earlier in the literature that education is more productive
the more volatile the state of technology (Nelson & Phelps, 1966; Griliches, 1969;
Welch 1970; Schultz, 1975).
A more selective rates of return estimate review focusing on the causality debate
between schooling and earnings (Card, 2001) reaffirms Griliches (1970) conclusion
that the effect of ability and related factors does not exceed 10% of the estimated
schooling coefficient. Instrumental variable (IV) estimates of the returns to education
based on family background are higher than classic Ordinary Least Squares estimates
based on the early work of Mincer, Becker and Chiswick (Becker & Chiswick,
1966; Mincer, 1974). The estimation method makes little difference on the returns
to education. The IV estimates are often higher than Ordinary Least Squares