nsw74psid1 {DAAG} | R Documentation |
This data frame contains 2675 rows and 10 columns. These data are pertinent to an investigation of the way that earnings changed, between 1974-1975 and 1978, in the absence of training. Data for the experimental treatment group (NSW) were combined with control data results from the Panel Study of Income Dynamics (PSID) study.
nsw74psid3
This data frame contains the following columns:
http://www.columbia.edu/~rd247/nswdata.html
Dehejia, R.H. and Wahba, S. 1999. Causal effects in non-experimental studies: re-evaluating the evaluation of training programs. Journal of the American Statistical Association 94: 1053-1062.
Lalonde, R. 1986. Evaluating the economic evaluations of training programs. American Economic Review 76: 604-620.
print("Interpretation of Regression Coefficients - Example 6.6") nsw74psid1.lm <- lm(re78~ trt+ (age + educ + re74 + re75) + (black + hisp + marr + nodeg), data = nsw74psid1) summary(nsw74psid1.lm)$coef options(digits=4) sapply(nsw74psid1[, c(2,3,8,9,10)], quantile, prob=c(.25,.5,.75,.95,1)) attach(nsw74psid1) sapply(nsw74psid1[trt==1, c(2,3,8,9,10)], quantile, prob=c(.25,.5,.75,.95,1)) pause() here <- age <= 40 & re74<=5000 & re75 <= 5000 & re78 < 30000 nsw74psidA <- nsw74psid1[here, ] detach(nsw74psid1) table(nsw74psidA$trt) pause() A1.lm <- lm(re78 ~ trt + (age + educ + re74 + re75) + (black + hisp + marr + nodeg), data = nsw74psidA) summary(A1.lm)$coef pause() A2.lm <- lm(re78 ~ trt + (age + educ + re74 + re75) * (black + hisp + marr + nodeg), data = nsw74psidA) anova(A1.lm, A2.lm)