The data in JTRAIN2 come from a job training experiment conducted for low-income men during 1976–1977; see Lalonde (1986). (i) Use the indicator variable train to determine the fraction of men receiving job training. (ii) The variable re78 is earnings from 1978, measured in thousands of 1982 dollars. Find the averages of re78 for the sample of men receiving job training and the sample not receiving job training. Is the difference economically large? (iii) The variable unem78 is an indicator of whether a man is unemployed or not in 1978. What fraction of the men who received job training are unemployed? What about for men who did not receive job training? Comment on the difference. (iv) From parts (ii) and (iii), does it appear that the job training program was effective? What would make our conclusions more convincing?

Which of the following is likely not a benefit of requiring a grand jury to listen to and examine all of the evidence against a person suspected of committing a serious crime and then independently deciding whether or not to hand down an indictment? 1.the grand jury system provides the accused another safeguard against being sent to trial and facing conviction based on flawed evidence. 2.the members of the grand jury are drawn from the community and are empowered to render independent decisions about whether or not the government has collected enough evidence to bring an individual to trial. 3.the grand jury’s decision can provide prosecutors insight into what is necessary to build a sufficient case if a similar crime is presented later. 4.the grand jury is impaneled to rubber-stamp prosecutors’ cases, which makes it possible for more cases to reach trial.