Applied Statistics and Econometrics II Fall 2021
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Applied Statistics and Econometrics II
Fall 2021
Problem Set 5
Please answer all questions and submit to NYUBrightspace no later than 10PM on Tues., 10/26/2021.
Part I Answer all questions
1) What is the definition of an unbiased estimator. Show that X is an unbiased estimator for E(Xi) = .
2) Describe the central limit theorem.
3) Describe the properties of the ML estimator.
4) Is the quasi-maximum likelihood estimator a consistent estimator?
5) How would you simulate random variables from a standard Normal distribution?
Part II Answer all questions
1) Suppose that the joint distribution of the two random variables x and y is
e− ( + )y (y)x
f (x, y) =
x!
where, y 0, x = 0,1, 2,....
Find the maximum likelihood estimators for and .
2) Consider the maximum likelihood estimation of a parameter and a test of the hypothesis H0: c() = 0. Describe the 3 basic approaches used for testing the hypothesis.
3) Explain how to construct an estimator from a set of population moment conditions using the generalized method of moments.
4) The method of moments estimator ˆ of the k-element vector β is defined as the solution to the sample moment condition n− 1i m(xi , yi , ˆ) = 0 corresponding to the assumed population moment condition Em(x, y, β) = 0, where x and y are random variables, and xi and yi , i = 1, . . . , n, are the observations, and m is a vector of moment functions.
a. How many elements are in the vector m(x, y, β)?
b. What are the dimensions of the matrix ' ?
c. Write an equation for estimating var(ˆ) .
5) The Poisson distribution has the following function form:
p(y | ) ye−, 0, y = 0,1, 2,...
E[y | ] =
var[y | ] =
Assume that y represents count data, meaning that it measures the number of times some event occurs in a fixed period of time.
a. Find the Jeffreys prior.
b. Assuming that you have a data set with n observations of the variable y, what is the likelihood function?
c. Find the posterior distribution?
2021-12-20