Questions from Econometrics

Q: Consider a simple time series model where the explanatory variable has classical

Consider a simple time series model where the explanatory variable has classical measurement error: yt = 0 + 1x*t + ut xt = x*t + et, where ut has zero mean and is uncorrelated with x*t and et. We o...

Q: Consider the simple regression model y = 0 + 

Consider the simple regression model y = 0 + 1x + u and let z be a binary instrumental variable for x. Use (15.10) to show that the IV estimator ^1 can be written as ^1 = (y1 - y0)/(x1 - x0), wher...

Q: Assume that u = x, so that the population

Assume that u = x, so that the population variation in the error term is the same as it is in x. Suppose that the instrumental variable, z, is slightly correlated with u: Corr(z, u) = .1. Suppose al...

Q: The following is a simple model to measure the effect of a

The following is a simple model to measure the effect of a school choice program on standardized test performance: score = 0 + 1choice + 2faminc + u1, where score is the score on a statewide test,...

Q: Suppose that the idiosyncratic errors in (14.4), {

Suppose that the idiosyncratic errors in (14.4), {uit: t = 1, 2, . . . , T}, are serially uncorrelated with constant variance, 2u. Show that the correlation between adjacent differences, (uit and (ui...

Q: In a random effects model, define the composite error vit =

In a random effects model, define the composite error vit = i + uit, where i is uncorrelated with uit and the uit have constant variance 2u and are serially uncorrelated. Define eit = vit - (vi, wh...

Q: Just prior to jury selection for O. J. Simpson’s murder

Just prior to jury selection for O. J. Simpson’s murder trial in 1995, a poll found that about 20% of the adult population believed Simpson was innocent (after much of the physical evidence in the cas...

Q: Suppose the following model describes the relationship between annual salary (salary

Suppose the following model describes the relationship between annual salary (salary) and the number of previous years of labor market experience (exper): Log(salary) = 10.6 + .027 exper. (i) What is...

Q: If a basketball player is a 74% free throw shooter,

If a basketball player is a 74% free throw shooter, then, on average, how many free throws will he or she make in a game with eight free throw attempts?

Q: Suppose the yield of a certain crop (in bushels per acre

Suppose the yield of a certain crop (in bushels per acre) is related to fertilizer amount (in pounds per acre) as (i) Graph this relationship by plugging in several values for fertilizer. (ii) Describ...