Cross-sectional data from the National Longitudinal Survey of Young Men (1966–1981) used by Card (1995) to estimate the return to schooling using college proximity as an instrument for education.
Format
A data frame with 3,010 observations and 33 variables:
- nearc2
Grew up near a 2-year college (binary).
- nearc4
Grew up near a 4-year college (binary).
- educ
Years of education.
- age
Age in years (1976).
- fatheduc
Father's years of education.
- motheduc
Mother's years of education.
- weight
NLS sampling weight.
- momdad14
Lived with both parents at age 14 (binary).
- sinmom14
Lived with single mother at age 14 (binary).
- step14
Lived with stepparent at age 14 (binary).
- reg661
Region dummy: New England (1966).
- reg662
Region dummy: Middle Atlantic (1966).
- reg663
Region dummy: East North Central (1966).
- reg664
Region dummy: West North Central (1966).
- reg665
Region dummy: South Atlantic (1966).
- reg666
Region dummy: East South Central (1966).
- reg667
Region dummy: West South Central (1966).
- reg668
Region dummy: Mountain (1966).
- reg669
Region dummy: Pacific (1966).
- south66
Lived in the South in 1966 (binary).
- black
Black (binary).
- smsa
Lives in SMSA (binary, 1976).
- south
Lives in the South (binary, 1976).
- smsa66
Lived in SMSA in 1966 (binary).
- wage
Hourly wage (cents, 1976).
- enroll
Enrolled in school in 1976 (binary).
- KWW
Knowledge of the World of Work test score.
- IQ
IQ score.
- married
Marital status (1976): coded 1–6 in the source data (1 = married; the remaining codes distinguish other marital statuses). Not a binary indicator; recode before use as a regressor.
- libcrd14
Had a library card at age 14 (binary).
- exper
Years of labor market experience (
age - educ - 6).- lwage
Log hourly wage.
- expersq
Experience squared (
exper^2).
Source
Card, D. (1995). "Using Geographic Variation in College Proximity to Estimate the Return to Schooling." In L.N. Christofides, E.K. Grant, and R. Swidinsky (Eds.), Aspects of Labour Market Behaviour: Essays in Honour of John Vanderkamp. University of Toronto Press.
Obtained from Stata's bcuse archive (Boston College),
bcuse card.
Redistribution basis: system.file("COPYRIGHTS", package = "ivreg2r").
Examples
data(card)
# IV regression: instrument education with college proximity.
# Control set from Card (1995, Table 2) / Wooldridge (2020), Example 15.4.
fit <- ivreg2(
lwage ~ exper + expersq + black + smsa + south + smsa66 +
reg662 + reg663 + reg664 + reg665 + reg666 + reg667 + reg668 + reg669 |
educ | nearc4,
data = card
)
summary(fit)
#>
#> 2SLS Estimation
#>
#> Call:
#> ivreg2(formula = lwage ~ exper + expersq + black + smsa + south +
#> smsa66 + reg662 + reg663 + reg664 + reg665 + reg666 + reg667 +
#> reg668 + reg669 | educ | nearc4, data = card)
#>
#> Observations: 3,010
#> VCV type: Classical (iid)
#>
#> Coefficients:
#> Estimate Std. Error z value Pr(>|z|)
#> (Intercept) 3.6661519 0.9223682 3.975 7.05e-05 ***
#> educ 0.1315038 0.0548174 2.399 0.016442 *
#> exper 0.1082711 0.0235956 4.589 4.46e-06 ***
#> expersq -0.0023349 0.0003326 -7.020 2.22e-12 ***
#> black -0.1467758 0.0537564 -2.730 0.006326 **
#> smsa 0.1118084 0.0315777 3.541 0.000399 ***
#> south -0.1446715 0.0272120 -5.316 1.06e-07 ***
#> smsa66 0.0185311 0.0215511 0.860 0.389862
#> reg662 0.1007677 0.0375854 2.681 0.007340 **
#> reg663 0.1482588 0.0367162 4.038 5.39e-05 ***
#> reg664 0.0498971 0.0436234 1.144 0.252701
#> reg665 0.1462719 0.0469387 3.116 0.001832 **
#> reg666 0.1629029 0.0517714 3.147 0.001652 **
#> reg667 0.1345722 0.0492708 2.731 0.006309 **
#> reg668 -0.0830770 0.0591734 -1.404 0.160332
#> reg669 0.1078142 0.0417024 2.585 0.009729 **
#> ---
#> Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1
#> ---
#> R-squared: 0.2382
#> Adj. R-squared: 0.2343
#> Wald chi2(15): 51.0 (p < 2.2e-16)
#> Root MSE: 0.3873
#>
#> Underidentification test (Anderson canon. corr. LM statistic):
#> Chi-sq(1) = 13.27 (p = 0.0003)
#>
#> Weak identification test:
#> Cragg-Donald Wald F: 13.26
#> Stock-Yogo critical values (IV size):
#> 10% maximal IV size 16.38
#> 15% maximal IV size 8.96
#> 20% maximal IV size 6.66
#> 25% maximal IV size 5.53
#>
#> Overidentification test (Sargan): (equation exactly identified)
#>
#> Weak-instrument-robust inference:
#> H0: B1=0 and orthogonality conditions are valid
#> Anderson-Rubin Wald F(1,2994) = 5.42 (p = 0.0200)
#> Anderson-Rubin Wald Chi-sq(1) = 5.44 (p = 0.0196)
#> Stock-Wright LM S Chi-sq(1) = 5.43 (p = 0.0197)
#>
#> Endogeneity test:
#> Chi-sq(1) = 1.17 (p = 0.2786)
#> Tested: educ
#>
#> First-stage diagnostics:
#> Endogenous F-stat p-value Partial R2 Shea PR2 SW F AP F
#> educ 13.26 0.0003 0.0044 0.0044 13.26 13.26
#>
#> Instrumented: educ
#> Included instruments: exper, expersq, black, smsa, south, smsa66, reg662, reg663, reg664, reg665, reg666, reg667, reg668, reg669
#> Excluded instruments: nearc4
#>