Practice Problems for Test 1 Econ 3200 - Introduction to Econometrics Cornell University
Spring 2010 Prof. Molinari
This practice problems have two parts totaling 100 points. I will maintain the same structure for the Test 1 that I am preparing for your c
Professor Francesca Molinari TAs Simon Kwok and Tae-Hoon Lim
Spring 2010
Introduction to Econometrics
Draft of Suggested Solutions to Problem Set 2
Economics 320
1. Question 2.2 from Wooldridge: In the equation Y = 0 + 1 X + u; subtract get Y 0 = 0 + 1 X
ECON 3200 Introduction to Econometrics
Answers for Problem Set 4
Problem 1 (Wooldridge 7.6)
In Section 3.3 – in particular, in the discussion surrounding Table 3.2 – we discussed
how to determine the direction of bias in the OLS estimators when an importa
Professor Francesca Molinari TAs Simon Kwok and Tae-Hoon Lim
Spring 2010
Introduction to Econometrics
Draft of Suggested Solutions to Practice Questions for Test 1
Economics 320
Part 1. a) A sequence of random variables Xn converges to X if
n!1
lim P (jXn
Problem Set 5 Practice for Prelim 2 Due Tuesday 04/13/10 at the beginning of class Econ 3200 - Introduction to Econometrics Cornell University
Spring 2010 Prof. Molinari
The exam will consist of TWO parts totaling 100 points. It will be a CLOSED BOOK exam
ECON 3200 Introduction to Econometrics
Answers for Problem Set 5
Problem 1 (Wooldridge 8.5)
1. No. For each coefficient, the usual standard errors and the heteroskedasticityrobust ones are practically very similar.
2. The effect is −.029(4) = −.116, so th
ECON 3200 Introduction to Econometrics
Problem set 5
(due date: April 2, 2009)
Problem 1 (Wooldridge 8.5) The variable smokes is a binary variable equal
to one if a person smokes, and zero otherwise. Using the data in smoke.xls
we estimate a linear probab
Homework 5
Due: Thursday, April 11
1.
1.1 Let cfw_ be dummy variables for mutually exclusive and exhaustive
categories. Prove that if one estimates the model
= 0 + 1 + 2 +
b
b
b
one will get 0 = =1 , 1 = =1 =1 , and 2 = =1 =1 , where =1 is
the sample a
Econ 3200: Introduction to Econometrics
Professor Stoye
First Prelim, March 7 , 2013
This exam consists of fteen questions, some of which are grouped to form a
larger question. Each question is worth 5 points.
Good luck!
1. Short Answer Questions.
1.1 If
Does High Public Debt Consistently Stie Economic
Growth? A Critique of Reinhart and Rogo
Thomas Herndon
Michael Ash
Robert Pollin
April 15, 2013
JEL codes: E60, E62, E65
Abstract
We replicate Reinhart and Rogo (2010a and 2010b) and nd that coding errors,
American Economic Review: Papers & Proceedings 100 (May 2010): 573578
http:/www.aeaweb.org/articles.php?doi=10.1257/aer.100.2.573
Growth in a Time of Debt
By Carmen M. Reinhart and Kenneth S. Rogoff*
In this paper, we exploit a new multi-country
historica
Homework 7
Due: Thursday, May 9
1. Consider the stochastic process
=
1 2
+
= 1 2
2
2
where is i.i.d. with mean 0 and variance 1 for 1.
1.1 Does ( ) depend on ? Does ( )?
1.2 Show that ( 1 ) = 12 and ( 2 ) = 13. What is
( ) for 2?
1.3 Is this process w
Homework 7
Due: Thursday, May 9
1. Consider the stochastic process
=
1 2
+
= 1 2
2
2
where is i.i.d. with mean 0 and variance 1 for 1.
1.1 Does ( ) depend on ? Does ( )?
1.2 Show that ( 1 ) = 12 and ( 2 ) = 13. What is
( ) for 2?
1.3 Is this process w
Homework 5
Due: Thursday, April 11
1.
1.1 Let cfw_ be dummy variables for mutually exclusive and exhaustive
categories. Prove that if one estimates the model
= 0 + 1 + 2 +
b
b
b
one will get 0 = =1 , 1 = =1 =1 , and 2 = =1 =1 , where =1 is
the sample a
Documentation for JEC Data
JEC contains weekly observations on prices and other factors from 1880-1886, for a total of n = 326 weeks. These data were provided by Professor Rob Porter of Northwestern University and were used in his paper "A Study of Cartel
Solution for Problem set 4 Econ 3200
Q1
(i) We need to compute the F statistic for the overall significance of the regression
with n = 142 and k = 4: F = [.0395/(1 .0395)](137/4) 1.41. The 5% critical
value with 4 numerator df and using 137 for the numera
Homework 4
Due: Tuesday, April 2
1. This question is about eciency of markets. Let return be the total
return from holding a rms stock from 1990 to 1994. The ecient markets hypothesis says that these returns should not be systematically related to informa
A Study of Cartel Stability: The Joint Executive Committee, 1880-1886
Author(s): Robert H. Porter
Source: The Bell Journal of Economics, Vol. 14, No. 2 (Autumn, 1983), pp. 301-314
Published by: RAND Corporation
Stable URL: http:/www.jstor.org/stable/30036
Econ 3200: Introduction to Econometrics
Professor Stoye
First Prelim, February 23 , 2012
This exam consists of four questions, each of which is worth 25 points.
Good luck!
1. Short Answer Questions (5 points each).
b
1.1 Let 1 be the OLS estimator in a si
Econ 3200: Introduction to Econometrics
Professor Stoye
Second Prelim, April 5
This exam consists of three questions. Points are distributed 20-50-30, with a
more detailed breakdown given below. Good luck!
1. Short Answer Questions (5 points each).
1.1 W
Professor Joerg Stoye
TAs Jun Sung Kim and Jos Mrio Lopes
Spring 2012
Economics 3200
Introduction to Econometrics
Suggested Solutions to Problem Set 1
(please contact us in case you find any typo)
1.
a. Note that X 2 is just anotehr random variable that c
Homework 2: Answer Key
1. In the equation y = 0 + 1 x + u; add and subtract
side to get
y = 0 + + 1 x + (u
):
Call the new error v = (u
new intercept is therefore (
on the right hand
); so that E(v) = E(u
) = E(u)
+
),
but
the
slope
is
still
0
1:
= 0. The
Solution for Problem Set 4 ECON 3200
(Please let us know if you find any typo, so we can correct it)
1.
1.1
Our Null is H 0 : 1 = 2 = 3 = 4 = 0 , which we will test at the 5% level.
We can compute the F statistic as
R2 / q
0.0395 / 4
F=
=
1.4085
2
(1 R )
Introduction to Econometrics
Spring 2012, Professor Stoye
Problem Set 1
Due: Thursday, 02/09/11
1 The following is the most recent poll of its kind posted on pollster.com
as this homework is being written.1
PPP (D) / Daily Kos / SEIU
1/26-29/12; 1,000 reg
Introduction to Econometrics
Spring 2012, Professor Stoye
Problem Set 2
Due: Tuesday, 02/21/12
1 Let = 0 + 1 + and suppose that (|) = () = 6= 0. Show
that this model can be rewritten as a model with the same slope (but dierent
intercept) and the property
Homework 3
Due: Tuesday, March 13
1. The following equation describes the median housing price in a community in terms of amount of pollution (nox for nitrous oxide) and average number
of rooms in houses in the community (rooms):
log = 0 + 1 log + 2 +
1.
4. Write down OLS
1
and plug-in
1 =
=
=
(x1i x
1 )
(x1i x
1 )
(x1i x
1 ) = 0. Also, we know
(x1i x
1 )
x1 = 0. Thus, we have
since
yi = 0 + 1 x1i + 2 x2i + ui .
That is,
P
P
(x1i x
1 )(0 + 1 x1i + 2 x2i + ui )
(x1i x
1 )yi
P
P
=
2
(x1i x
1 )
(x1i x
1 )2
Homework 4
Due: Thursday, April 5
1. This question is about eciency of markets. Let return be the total
return from holding a firms stock from 1990 to 1994. The ecient markets hypothesis says that these returns should not be systematically related to info
ECON 3200
Spring 2012
Homework 3 Solutions
1.
2.
(i) Because ShareF = 1 ShareP ShareI ShareS, including ShareF in a regression
would create the multicollinearity problem.
(ii) A change in ShareP by 1 unit is associated with a change in growth by 1 units.
WAGE2.DES
wage
hours
married black
IQ
KWW
south
educ
urban
exper
sibs
tenure age
brthord meduc
lwage
Obs: 935
1. wage
monthly earnings
2. hours
average weekly hours
3. IQ
4. KWW
IQ score
knowledge of world work score
5. educ
years of education
6. exper
ye