Quantitative Approaches to
International Relations
 Case Study of Research Design in the
International Political Economy
 Case Study of Research Design in
International Environmental Policy
 Case Study of Research Design in
International Security Studies
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Why Quantitative Analysis? Allows
inferences about reality using the law of
probability.
 How? Through large aggregate of cases
your able to draw relationships between
elements and check if the relationship is
by chance or purposeful.
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Linear Correlation- r
 Multiple Regression- R Squared
 P-Value
 Analysis of Variance- ANOVA
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The Correlation Coefficient: Definition
Bruce Ratner, Ph.D.
The correlation coefficient, denoted by r, is a measure of the strength of the straight-line
or linear relationship between two variables. The correlation coefficient takes on values
ranging between +1 and -1. The following points are the accepted guidelines for
interpreting the correlation coefficient:
0 indicates no linear relationship.
+1 indicates a perfect positive linear relationship: as one variable increases in its values,
the other variable also increases in its values via an exact linear rule.
-1 indicates a perfect negative linear relationship: as one variable increases in its values,
the other variable decreases in its values via an exact linear rule.
Values between 0 and 0.3 (0 and -0.3) indicate a weak positive (negative) linear
relationship via a shaky linear rule.
Values between 0.3 and 0.7 (0.3 and -0.7) indicate a moderate positive (negative)
linear relationship via a fuzzy-firm linear rule.
Values between 0.7 and 1.0 (-0.7 and -1.0) indicate a strong positive (negative) linear
relationship via a firm linear rule.
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The value of r squared is typically taken as “the
percent of variation in one variable explained by the
other variable,” or “the percent of variation shared
between the two variables.”
Linearity Assumption. The correlation coefficient
requires that the underlying relationship between the
two variables under consideration is linear. If the
relationship is known to be linear, or the observed
pattern between the two variables appears to be
linear, then the correlation coefficient provides a
reliable measure of the strength of the linear
relationship. If the relationship is known to be
nonlinear, or the observed pattern appears to be
nonlinear, then the correlation coefficient is not
useful, or at least questionable.
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A p-value is a statistical value that details
how much evidence there is to reject
the most common explanation for the
data set. It can be considered to be the
probability of obtaining a result at least
as extreme as the one observed, given
that the null hypothesis is true.
Theory should determine the research
design, not vice versa.
 The Hypothesis and the
operationalization of variables should
drive the methodology
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The Ability not just to describe
association among phenomena but to
calculate the probabilities that such
associations are the product of chance
 The ability to gain a better
understanding of the sources of human
behavior in international affairs
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Errors of Specification: 3 Types of Errors
 1. Too much effort calculating
correlations with little or no attention to
theory
 2. Theory itself often is weak and difficult
to test because it is too imprecise or too
shallow
 3. Empirical researchers often impose a
statistical model on the theory instead of
crafting a model to test the theory
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Errors of Inference:
1. Overemphasis in statistical significance while neglecting
substantive significance
2.Small Sample Size
3. Single Test Bias rather than multiple testing for reliability
4. Lakatos View: Your it till I find something better
vs. Bayesian View-Cumulation of results
5.Garbage Can Models: Too many variables, attempt to
limit the variables
6.Computer Error
The Effects of Hegemony on Trade
The Effects of Alliances, PTA, and Trade
The Effects of Political Conflict on Trade
1970: 20% of Research in
the IPE used Quantitative
Methodology
Other
Research
Methods
Quant.
1980: 25% of Research in
the IPE used Quantitative
Methodology
Other
Research
Methods
Quant.
1990: 45% of all research in the IPE used
Quantitative Methodology
Other Research
Methods
Quant.
Problem: How do you define, and
operationalize Hegemony?
 Many have tried and failed to reject the
Null Hypothesis: There is no relationship
between Hegemony and Trade
 Until the definition of Hegemony was
operationalized by viewing Benevolent and
Malign Hegemony, and viewing the effect
of alliances in Bi-polar and Multi-polar
environment
 Reaffirming that Theory leads the Research
Method
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Increased Trade with Non-Major Powers in
Percentage
No PTA/ Yes Ally
Increased Trade with
Non-Major Powers in
Percentage
Yes PTA/No Ally
PTA/Alliance
0
50
100
150
Increased Trade with Major Powers in
Percentage
No PTA/ Yes Ally
Increased Trade with
Major Powers in
Percentage
Yes PTA/No Ally
PTA/Alliance
0
50
100
150
Gravity Model of Distance and Trade
with added variable for Diplomatic
Relations
 Results: Cooperation stimulates trade;
Threats had no statistical significance;
War hampers trade
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5 Central Themes of Research:
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The effect of economic development(IV), abatement costs(IV),
and democracy(IV) on the pollutions patterns(DV)
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The effect of growing trade(IV) on environmental
degradation(DV)
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The effect of regulatory issues(IV) on the environment(DV)
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The relationship between environmental factors(IV) and violent
conflict(DV)
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The formation of effectiveness of international regimes(IV) and
environmental degradation(DV)
Larger and more comprehensive
datasets relevant to International
Environmental Policy are needed
 Small Sample Sizes making it difficult to
ascertain reliability of studies
 Problem of conceptual consolidation:
How do you unify different concepts of
resource expenditures and problemsolving models
 Measuring Effectiveness
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Four Stages of International Disputes:
 Dispute Initiation Stage
 Challenge the Status Quo Stage
 Negotiation Stage
 Military Escalation Stage
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Appropriate Measurements, which unit of
analysis to use, and mode of analysis: Crosssectional time series
Selection Bias: one solution stratified
random sampling using both conflict and
non-conflict variables
Non-Independent observations
Inadequate Measurements-Solutions by
Stage:
Military Balance measure
Dyadic Analysis
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https://controls.engin.umich.edu/wiki/ind
ex.php/Basic_statistics:_mean,_median,_
average,_standard_deviation,_zscores,_and_p-value