wooldridge (version 1.4-4)

card: card

Description

Wooldridge Source: D. Card (1995), Using Geographic Variation in College Proximity to Estimate the Return to Schooling, in Aspects of Labour Market Behavior: Essays in Honour of John Vanderkamp. Ed. L.N. Christophides, E.K. Grant, and R. Swidinsky, 201-222. Toronto: University of Toronto Press. Professor Card kindly provided these data. Data loads lazily.

Usage

data('card')

Format

A data.frame with 3010 observations on 34 variables:

• id: person identifier

• nearc2: =1 if near 2 yr college, 1966

• nearc4: =1 if near 4 yr college, 1966

• educ: years of schooling, 1976

• age: in years

• fatheduc: father's schooling

• motheduc: mother's schooling

• weight: NLS sampling weight, 1976

• momdad14: =1 if live with mom, dad at 14

• sinmom14: =1 if with single mom at 14

• step14: =1 if with step parent at 14

• reg661: =1 for region 1, 1966

• reg662: =1 for region 2, 1966

• reg663: =1 for region 3, 1966

• reg664: =1 for region 4, 1966

• reg665: =1 for region 5, 1966

• reg666: =1 for region 6, 1966

• reg667: =1 for region 7, 1966

• reg668: =1 for region 8, 1966

• reg669: =1 for region 9, 1966

• south66: =1 if in south in 1966

• black: =1 if black

• smsa: =1 in in SMSA, 1976

• south: =1 if in south, 1976

• smsa66: =1 if in SMSA, 1966

• wage: hourly wage in cents, 1976

• enroll: =1 if enrolled in school, 1976

• KWW: knowledge world of work score

• IQ: IQ score

• married: =1 if married, 1976

• libcrd14: =1 if lib. card in home at 14

• exper: age - educ - 6

• lwage: log(wage)

• expersq: exper^2

Notes

Computer Exercise C15.3 is important for analyzing these data. There, it is shown that the instrumental variable, `nearc4`, is actually correlated with `IQ`, at least for the subset of men for which an IQ score is reported. However, the correlation between `nearc4`` and `IQ`, once the other explanatory variables are netted out, is arguably zero. At least, it is not statistically different from zero. In other words, `nearc4` fails the exogeneity requirement in a simple regression model but it passes, at least using the crude test described above, if controls are added to the wage equation. For a more advanced course, a nice extension of Card's analysis is to allow the return to education to differ by race. A relatively simple extension is to include black education (blackeduc) as an additional explanatory variable; its natural instrument is blacknearc4.

Used in Text: pages 526-527, 547

Examples

 str(card)