Introduction to Empirical Analysis and Quantitative Methods
POL SCI 3

Fall 2015
Week 4 Quiz:
Game Theory
Reminder: The rst midterm is in one week! It includes game theory.
1. Dene Nash Equilibrium.
2. In an authoritarian regime, there are two groups of citizens, the working class and the
elite. Each group has has two strategies: revo
Introduction to Empirical Analysis and Quantitative Methods
POL SCI 3

Fall 2015
PS 3
Fall 2015
Understanding Experiments
A researcher is interested in studying the effects of negative campaign ads on viewers attitudes
towards voting. She hypothesizes that negative campaign ads will lead voters to abstain from
voting on election day.
Introduction to Empirical Analysis and Quantitative Methods
POL SCI 3

Fall 2015
Political Science 3 GSI: Katherine Michel
Descriptive Statistics Worksheet
1. The following table contains death rates from firearms injuries in selected countries (U.S.
Bureau of the Census, 1999):
Country
United States
Australia
Canada
Denmark
England a
Introduction to Empirical Analysis and Quantitative Methods
POL SCI 3

Fall 2015
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Introduction to Empirical Analysis and Quantitative Methods
POL SCI 3

Fall 2015
Activity 9
Part 1: Draw the probability distribution and sampling distribution for each
of the following.
a) A fair coin is ipped 100 times.
b) A biased coin (60% heads, 40% tails) is ipped 100 times.
c) 1000 people are randomly selected out of a populati
Introduction to Empirical Analysis and Quantitative Methods
POL SCI 3

Fall 2015
Activity 10
Important Formulas
(EO)2
E
Categorical IV and Categorical DV: X 2 =
Degrees of Freedom=(r1)(c1); r is # of rows in table, c is # of columns in table
Categorical IV and Continuous DV: t =
s2 =
Y1 Y2
;
SE(Y1 Y2 )
s2
1
n1
SE(Y1 Y2 ) =
+
s2
2
Introduction to Empirical Analysis and Quantitative Methods
POL SCI 3

Fall 2015
PS 3
Fall 2015
Doing the Math  Bivariate Regression
Lets take a look at the sample regression formula:
1. Why do some of the characters have hats on top of them?
2. How is this formula different from the population regression formula? Write it down below
Introduction to Empirical Analysis and Quantitative Methods
POL SCI 3

Fall 2015
Activity 11
1. Some researchers take a random sample of students at Berkeley. They nd that 77% of
the 150 students from outside California approve of the local restaurant options (SD=40%),
whereas 70% of the 240 students from inside California approve of
Introduction to Empirical Analysis and Quantitative Methods
POL SCI 3

Fall 2015
Bivariate Regression Practice
1. This Stata output comes from data1 on student exam scores and time
spent studying. The variable rhours refers to how many hours the student
spent studying, and the variable rscore refers to their exam score.
a. What is the
Introduction to Empirical Analysis and Quantitative Methods
POL SCI 3

Fall 2015
PS 3, Sections 104/105 Michel
Practice with Causality and Experiments
1. A researcher consults census data and finds that the more police officers cities hire, the
higher the crime rates in those places. Assess whether the researcher can claim causality.
Introduction to Empirical Analysis and Quantitative Methods
POL SCI 3

Fall 2015
PS 3, Sections 104/105 Michel
Practice with Causality and Experiments: Answer Key
1. Because the researcher is simply looking at preexisting census data, this is an
observational study, not an experiment. If the researcher looked only at census data from
Introduction to Empirical Analysis and Quantitative Methods
POL SCI 3

Fall 2015
Midterm Review
Section 110
1. Descriptive statistics.
a. What are the median and mean of this data?
Y = (2, 3, 18, 10, 7)
b. What are the mean and standard deviation of the following
data? Even if you can do it in your head, show your work.
Y = (3, 7, 3,
Introduction to Empirical Analysis and Quantitative Methods
POL SCI 3

Fall 2015
Review Problems1 (Updated)
1. Three friends are deciding how to spend a Saturday. Their preferences are as follows:
Adam: Play videogames (V), go for a walk (W), go hiking (H).
Beth: Go for a walk (W), go hiking (H), play videogames (V).
Carlos: Go hiking
Introduction to Empirical Analysis and Quantitative Methods
POL SCI 3

Fall 2015
Week 3 Quiz
1. Members of the Cal chapter of the Harry Potter Fan Club have the following
preferences for J.K. Rowling characters:
Priya
Ming
Serena
Brett
<>
Neville
Hermione
Ron
Voldemort
(N)
(H)
(R)
(V)
What is the preference ordering for eac
Introduction to Empirical Analysis and Quantitative Methods
POL SCI 3

Fall 2015
PS 3 2015
Game Theory: Games Theory Practice Problems
Most of these questions (aside from problem 2) were written by Katherine Michel.
Question One
Two states, say Algeria and Mali, are deciding whether to build nuclear weapons.
 If exactly one state dec
Introduction to Empirical Analysis and Quantitative Methods
POL SCI 3

Fall 2015
Midterm Review II Answers
Note that in some cases, alternative answers to these questions could also be correct.
1. a. median = 7; mean = 8
1. b. mean = 5; standard deviation = 2
1. c. X has the higher mean and Y has the greater dispersion.
1. d. The medi
Introduction to Empirical Analysis and Quantitative Methods
POL SCI 3

Fall 2015
PS 3
Fall 2015
Research Design and Measurement
The Study:
A Ph.D. student wants to study the effects of various campaign strategies on voter turnout.
Specifically, she wants to see the different effects of mailed fliers with party/candidate
information to
Introduction to Empirical Analysis and Quantitative Methods
POL SCI 3

Fall 2015
Causality and Experiments Practice
1. A researcher is studying the effects of education on poverty in rural
settings. He travels to a rural area in Pakistan and sets up education
programs for adults and children in five villages, then records income in
th
Introduction to Empirical Analysis and Quantitative Methods
POL SCI 3

Fall 2015
PS 3
Fall 2015
Research Design and Measurement
The Study:
A Ph.D. student wants to study the effects of various campaign strategies on voter turnout.
Specifically, she wants to see the different effects of mailed fliers with party/candidate
information to
Introduction to Empirical Analysis and Quantitative Methods
POL SCI 3

Fall 2015
PS 3: Sections 104/105 Michel
Research Design, Causal Claims, and Validity
Scenario One: A researcher wants to know if there is a relationship between the average number
of hours that college students sleep per night and their grade point average.
Propo
Introduction to Empirical Analysis and Quantitative Methods
POL SCI 3

Fall 2015
Week 10 Warmup
1. Examine the distribution below. Imagine you sampled 1000 observations from this
distribution. Draw the likely distribution of this sample.
2. Examine the distribution below. Imagine you sampled from the distribution and calculated the m
Introduction to Empirical Analysis and Quantitative Methods
POL SCI 3

Fall 2015
Week 7 Handout
1. Consider the following theory: Direct democracy (where citizens vote directly for policies) causes lower spending on education as compared to representative democracy
(where citizens elect representatives who chose policies).
a. Imagine
Introduction to Empirical Analysis and Quantitative Methods
POL SCI 3

Fall 2015
Week 6 Problems: Causality and Experiments
Causality Consider the Four Causal Hurdles posed by Kellstedt and Whitten:
Is there a credible mechanism linking X and Y?
Is there covariation between X and Y? (In the cases below, you can assume yes).
Are we
Introduction to Empirical Analysis and Quantitative Methods
POL SCI 3

Fall 2015
Week 6 Quiz: Causality
Reminder: The next homework is due on Monday!
1. Men are more likely to vote Republican. What type of relationship is this?
a. A deterministic relationship.
b. A confounding relationship.
c. A probabilistic relationship.
d. A multiv
Introduction to Empirical Analysis and Quantitative Methods
POL SCI 3

Fall 2015
PS 3: Hypothesis Testing
Jason Wittenberg
University of California, Berkeley
Wittenberg (UC Berkeley)
PS 3: Hypothesis Testing
1 / 48
Goals of this lecture
Well learn several ways to evaluate relationships between X and Y .
Well learn how to identify a re
Introduction to Empirical Analysis and Quantitative Methods
POL SCI 3

Fall 2015
PS 3: Midterm #2 Review
Andrew Bertoli, Demetria McAleer, Katherine Michel
UC Berkeley
October 26, 2015
Logistics
Exam will start promptly at 4:10 pm. Please arrive early
and spread out as much as possible.
You do not need a blue book.
You do not need a c
Introduction to Empirical Analysis and Quantitative Methods
POL SCI 3

Fall 2015
Name:_
GSI:_
Political Science 3 Homework # 2
Note: It is highly recommended that you show your work. Partial credit may be
given for incorrect answers if the work shows that you made a simple error. On the
questions that specifically ask you to show your
Introduction to Empirical Analysis and Quantitative Methods
POL SCI 3

Spring 2013
12/15/2014
StudyBlue printing of POLI 3 Study Guide (201415 Stoker)
POLI 3 Study Guide (201415 Stoker)
StudyBlue Sat Dec 13 19:27:52 CST 2014
Static Group Comparison
XO O
Observational study (nonquasi experimental).
Two or more groups who vary in terms