Question 1: Suppose you are asked to conduct a study to determine whether smaller classes lead to improved student performance for fourth grade

a.If you conduct any experiment you want, what would you do? Be specific?

b. More realistically, suppose you can collect observational data on several thousand fourth grades in a given state. You can obtain the size of their fourth grade class and standardized test score taken at the end of the fourth grade. Why might you expect a negative correlation between class size and test score?

c. Would a negative correlation necessarily show that smaller class sizes cause better performance? Explain?

Question 2: A justification of job training program is that they improve worker productivity. Suppose that you are asked to evaluate whether are more job training makes worker more productive.  However rather than having data of individual workers, you have access to data on manufacturing firms in ohio. In particular in each firm you have information of hours of job training per worker (training) and number of non-defective item produced per worker hour(output).

a. Carefully state the ceteris paribus thought experiment underplaying this policy question.

b. Does it seem likely that a firm decision to train its worker will be independent of worker characteristics? What are the some measurable and immeasurable workers characteristics?

c.  Name a factor other than worker characteristics that can affect work productivity?

d.  If you find a positive correlation between output and training, would you have convincingly established that job training makes workers more productive? Explain…

Question 3: Suppose at your university you are asked to find the relationship between weekly hours spent (study) and weekly hours spent (work). Does it make sense to characterize the problem as inferring whether study causes work or work causes study? Explain?