nsw74psid1 | R Documentation |

## Labour Training Evaluation Data

### Description

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.

### Usage

nsw74psid1

### Format

This data frame contains the following columns:

- trt
a numeric vector
identifying the study in which the subjects were enrolled
(0 = PSID, 1 = NSW).

- age
age (in years).

- educ
years of education.

- black
(0 = not black, 1 = black).

- hisp
(0 = not hispanic, 1 = hispanic).

- marr
(0 = not married, 1 = married).

- nodeg
(0 = completed high school, 1 = dropout).

- re74
real earnings in 1974.

- re75
real earnings in 1975.

- re78
real earnings in 1978.

### Source

http://www.columbia.edu/~rd247/nswdata.html

### References

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.

### Examples

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)