University of California
Department of Economics
D. Steigerwald
Economics 140A
Exercise 1
1.
You are interested in purchasing a home in Santa Barbara. To determine if it is a good
time to buy, you collect the selling prices of all homes in the city over t
Economics 140A
Fall 2011
Professor Startz
Answers to Homework 2
1.
a)
b)
c)
.
2.
a)
b)
c)
d)
3.
a) The sample mean is
. The sample median is the value in the middle, 2.0. The
sample variance is
4. Since the data is normal, so is the mean. Since the no
Economics 140A
Spring 2015
Homework 1
Your first job is to predict the stock market, specifically the Dow Jones Industrial Average (DJIA).
Go look up the two most recent DJIA and write them down.
Here is the data for 15 consecutive trading days in March 2
Economics 140A
Fall 2011
Professor Startz
Sketched Answers to Homework 3
1. Your profit function is
(
)
(
(
) (
)
(
(
2. We have
(
(
From earlier results, we know
( )
(
)
(
)
)
(
(
.
(
)
(
)
)
(*( )
)
)
Write an alternative estimator, , as a linear functi
Economics 140A
Answers to Exercise 1
1. (From Fall 1992 nal examination.)
a) To assess the quality of estimates obtained from the actual sales prices
of homes, we must determine the statistical properties of the estimators from
which the estimates are con
Economics 140A
Spring 2015
Homework 3
Note: In this assignment, CPS data refers to the file cps_march_2014.wf1
1. Use the data set cdcosts2015 to estimate the marginal cost of one more CD. (Regress costs
on the number of CDS.) Test the hypothesis that the
Problem Set 1
Economics 140A
August 10, 2016
1. Since we assume that cfw_Pt 497
t=1 are i.i.d, let us suppose from now on that the mean E(Pt ) = and
V ar(Pt ) = 2 .
(a) An estimator for the mean is P =
denotes the j-th order statistics.
1
497
P497
t=1 Pt
University of California
Department of Economics
Doug Steigerwald
Introduction to Econometrics
Economics 140A
Course Prerequisites:
Students should be familiar with calculus (Mathematics 3A-3C), the fundamentals of
statistical inference (Statistics 120A)
Economics 140A
Spring 2015
Homework 2
1.
Suppose you are given a data sample of three independent observations. The three
values are cfw_3,5,4. For this question, show how youre doing the calculations rather than
use a computer.
What is the sample mean?
5021-1-1
FBE 555 Midterm Exam
Midterm Exam
Please do not open this exam until you are told to do so.
Instructions:
A. You may complete this exam with a blue or black pen or a sharp pencil.
B. There are 8 questions in this exam.
C. There are 110 points pos
6003-1-1
FBE 555 Midterm Exam
Midterm Exam
Please do not open this exam until you are told to do so.
Instructions:
A. You may complete this exam with a blue or black pen or a sharp pencil.
B. There are 6 questions in this exam.
C. There are 100 points pos
Economics 140A
Winter 2014
Stearns and Wright
Homework 3
1. The variance of the OLS estimator is var = 2 if our usual assumptions hold. Suppose
2
2.
that = + 5 + 2 and = + 5, so is biased but all of our other assumptions
hold. What is var ?
a. Find the
Economics 140A
Winter 2014
Sketched Out Answers for Quiz 1
Note that not all the details are shown here. The sketches here are just to point you in the right
direction. A good exam answer would have more details.
Question: Let:
X ~ N(0,4)
(a) Find ().
Y =
Economics 140A
Winter 2014
Fischer/Stearns/Wright
Homework 4
Use our CPS data for this homework.
Consider the regression
= 0 + 1 + 2 + 3 2 + 4 + 5 + 6
+ 7 + 8 + 9
1. Give point estimates for salaries for the following (you might want to use Excel to sa
Economics 140A
Answers to Exercise 3
1. (Fall 1995 Final Examination)
a) The OLS estimator of is
Pn
Xt Yt
t
B = P=1
n
2=
t=1 Xt
Pn
Xt Ut
t
+ P=1
n
2:
t=1 Xt
Because Xt is exogenous and EUt = 0,
Pn
t=1 Xt EUt
EB = + Pn
=:
2
t=1 Xt
The variance of the OLS e
Economics 241B
Answers to Exercise 7
1.
(Final Examination, Economics 241B, Winter 2004)
a.
For the classic linear regression model, identication of
mulitiplying both sides of the regression by Xt :
1
follows from
Xt Yt = Xt2 + Xt Ut :
Taking the expectat
University of California
Department of Economics
D. Steigerwald
Economics 140A
Exercise 1
1.
You are interested in purchasing a home in Santa Barbara. To determine if it is a good
time to buy, you collect the selling prices of all homes in the city over t
Economics 140A
Fall 2011
Professor Startz
Homework 2
You may find the lecture notes Review of Statistics and Chapter R of the text helpful.
1.
The random variable x can only take three possible values: 1 with prob=0.3, 2 with
prob=0.3 and 3 with prob=0.4.
University of California
Department of Economics
D. Steigerwald
Economics 140A
Problem Set VI
1.
You wish to analyze (personal) health care expenditures as a function of income and
health status. From a national health survey of n individuals you obtain
S
Economics 140A
Spring 2015
Quiz 1
Answer all 4 questions. Each question is worth 15 points, although some questions are easier
than others. Be sure to show your work for each question.
Write your answers on the pages provided separately from the test book
Economics 140A
Fall 2011
Professor Startz
Sketched Answers to Homework 5
1.
a. The formula for the OLS variance under heteroskedasticity is
(
( )
)
In this case thats just
( )
(
)
b. The GLS estimator requires dividing each observation by its correspondin
University of California
Department of Economics
D. Steigerwald
Economics 140A
Problem Set III
1.
Let Y1,Y2,.,Yn be a random sample from a population with mean and variance 2.
Thus each Yi is an independently and identically distributed (i.i.d.) random va
Economics 140A
Winter 2014
Wright/Stearns
Homework 5
2
1. Consider the regression = + . There are = 1 + 2 observations and ( ) = 1
2
for the first = 1,2, , 1 observations, while ( ) = 2 for the last = 1 + 1, 1 +
2, , 1 + 2 .
a. Derive the variance of . (Y
Economics 140A
Winter 2014
Stearns and Wright
Homework 2
You may find the first weeks lecture notes and Chapter R of the text helpful.
1.
The random variable x can only take three possible values: 1 with prob=0.3, 2 with
prob=0.3 and 3 with prob=0.4.
a. W
Economics 140A
Fall 2011
Professor Startz
Homework 5
1. Consider the regression
for the first
.
. There are
observations, while
()
observations and
for the last
()
a. Derive the variance of . (You may use the formula for OLS variance under
heteroskedastic
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University of California
Department of Economics
D. Steigerwald
Economics 140A
Exercise 3
1.
Consider the model
Yt = Xt + Ut, t = 1,2,.,n,
where Xt is the period-t value of an exogenous variable with mean zero, is an unknown
parameter, the period-t error
University of California
Department of Economics
D. Steigerwald
Economics 140A
Exercise 6
1.
Assume the population regression model is
(1)
Yt* X t* U t
where all variables are expressed as deviations from their respective sample means. Let B
be the OLS es
University of California
Department of Economics
D. Steigerwald
Economics 140A
Exercise 1
1.
You are interested in purchasing a home in Santa Barbara. To determine if it is a good
time to buy, you collect the selling prices of all homes in the city over t