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This is a subsample of the data from the treated group in the National Supported Work Demonstration (NSW) and the comparison sample from the Population Survey of Income Dynamics (PSID). This data was previously analyzed extensively by Lalonde (1986) and Dehejia and Wahba (1999).


A data frame with 614 observations (185 treated, 429 control). There are 9 variables measured for each individual.

  • "treat" is the treatment assignment (1=treated, 0=control).

  • "age" is age in years.

  • "educ" is education in number of years of schooling.

  • "race" is the individual's race/ethnicity, (Black, Hispanic, or White). Note previous versions of this dataset used indicator variables black and hispan instead of a single race variable.

  • "married" is an indicator for married (1=married, 0=not married).

  • "nodegree" is an indicator for whether the individual has a high school degree (1=no degree, 0=degree).

  • "re74" is income in 1974, in U.S. dollars.

  • "re75" is income in 1975, in U.S. dollars.

  • "re78" is income in 1978, in U.S. dollars.

"treat" is the treatment variable, "re78" is the outcome, and the others are pre-treatment covariates.


Lalonde, R. (1986). Evaluating the econometric evaluations of training programs with experimental data. American Economic Review 76: 604-620.

Dehejia, R.H. and Wahba, S. (1999). Causal Effects in Nonexperimental Studies: Re-Evaluating the Evaluation of Training Programs. Journal of the American Statistical Association 94: 1053-1062.