ECON 422
Spring 2016
Youngjin Yun
University of Maryland
Problem Set 1
Due on Thursday, February 11, at 9:30am. Show your work step by step, answer concisely and
write clearly. You may work in groups, but each student must submit her own answers. In the c
ECON 422 Introductory Econometrics I
Problem Set 1: Solutions
Yiqun Chen
Department of Economics
University of Maryland
September 18, 2014
1. Complete the following statements:
n
(a)
i=1
n
(b)
i=1
xi
n
1
n
=
1
n
n
xi
i=1
(a + b) = a + b
(c) log(x y ) = lo
I a)
SL R
~',
=:.
~ a
+
~I
Xi
T
U,
~
)
XI
G\ '"'
d
Lt, The rr C del ,.
i: q 1,e,
Sly.(
'l.:
l J
Thv
I
x, j
., oS
" ,) 1".
Ct
ra"do"'1
5
V CAr', CAi lOti
Cj
N'lf
{e
:x
"
Sl.R.
.3
.$0"Q.
,"
[
' ,
X
,}
)
=1=-<:
V
5
In class problems some answers
January 22, 2013
1) Find the critical t values in the following cases:
a) n = 4, = 0.05 (two-tailed test) 3.182 ( 3 d.f.)
b) n = 4, = 0.05 (one-tailed test) 2.353 (3 d.f.)
c) n = 14, = 0.01 (two-tailed test) 3.012 (13 d.f.)
ECON 422 Introductory Econometrics I
Problem Set 2: Solutions
Yiqun Chen
Department of Economics
University of Maryland
October 5, 2014
1. The following is data on the number of children (kids) and the years of schooling (educ) for a sample
of six married
Econ422: Introductory Econometrics
Review for Midterm I: Concepts
University of Maryland, Department of Economics
Instructor: Yiqun Chen, Fall 2014
Note: These questions are meant to get you STARTED in preparing for the
exam. There will be NO multiple cho
Spring 2014
ECON422 Computer Project 1
University of Maryland
Department of Economics
Prof. Razvan Vlaicu
Student Name: _
February 21, 2014
DUE Friday February 28, at 4pm, in 3114 Tydings
Computer Project 1
(Based on Computer Exercise C2.2 in Wooldridge)
University of Maryland, Department of economics
ECON 422: Econometrics I
Q10
Names:
1. Using research and development data, we estimated the effect of sales (in millions of dollars) on R&D
expenditures as percentage of sales:
rd in ens 2.613 0.00030sales
University of Maryland, Department of economics
ECON 422: Econometrics I
Q11
Names:
1. Using a data set on students performance and their characteristics, we estimated the following model:
stndfnl 2.05 0.0097atndrte 1.63 priGPA 0.128ACT 0.296 priGPA2 0.0
University of Maryland, Department of economics
ECON 422: Econometrics I
Q20
Names:
1. (Example 13.9: County crime rates in Northern Carolina) Using panel data on 90 counties in NC for 1981-1987
we estimate a simple version of Cornwell and Trumbull (1994
University of Maryland, Department of economics
ECON 422: Econometrics I
Q13
Names:
1. Using data on 13379 workers, Krueger (1993) studied the effect of computer usage on wage:
log(wage) 1.8 0.117compw 0.070comph 0.017compw.comph 0.051edu 0.0071edu.comph
University of Maryland, Department of economics
ECON 422: Econometrics I
Q14
Names:
1. Goldman and Romley studied the demand for Cedars Sinai vs. UCLA hospital by analyzing data from Medicarecovered patients in Los Angeles area. The following model is es
University of Maryland, Department of economics
ECON 422: Econometrics I
Q15
Names:
1. Using a data on college performance, we estimated the following model for the fall and second semester for
athlete students:
trmgpa 2.12 0.900crsgpa 0.193cumgpa 0.0014
University of Maryland, Department of economics
ECON 422: Econometrics I
Q19
Names:
1. (Example 13.2: change in return to education over time) A log(wage) equation pooled across the year 1978 (the
base year) and 1985 is given in the following equation:
l
University of Maryland, Department of economics
ECON 422: Econometrics I
Q16
Names:
1. The variable smoke is a binary variable equal to one if a person smokes, and zero otherwise. Using a data set, we
estimated the following linear probability model:
smo
University of Maryland, Department of economics
ECON 422: Econometrics I
Q17
Names:
1. The effect of antidumping filing on the import of chemicals is estimated using monthly data in the following
model.
. reg
lchnimp lchempi lgas lrtwex befile6 affile6 a
University of Maryland, Department of economics
ECON 422: Econometrics I
Q12
Names:
1. The following model is a simplified version of a multiple regression model to study the tradeoff
between time spent sleeping and working and to look at other factors a
University of Maryland, Department of economics
ECON 422: Econometrics I
Q18
Names:
1. The effect of individual lags in a Finite Distributed Lag Model can be estimated imprecisely because of
multicolinearity. One way to alleviate this problem is to assum
Econ 422
Sergio Urzua
PRACTICE EXAM
The notation here follows the same notation used in the lectures.
Short Questions
Please answer True or False. Answer without explanation will not receive credits. Full credit
requires a formal proof.
(a) Suppose you wa
3/30/14
Educa,on and Development
Econ 315 - Stefania Scandizzo
1
Physical capital vs. human capital
What are human capital investments?
Formal educa,on
Health
On-the-job training
Today we will focus on SCHOOLI
Lecture 6
OLS Asymtotics
6.1
Large Sample Properties
Consider a random sample Y1 , Y2 , , Yn with mean and variance 2 .
P
Derive V ar(Y ), where Y = n1 ni Yi
What happens to V ar(Y ) as n goes to infinity?
Large Sample Properties
Unbiasedness and effic