BSSn4495:
Qualitative
research in
security
studies
The logic of
process tracing
March 22, 2022
Miriam Matejova, PhD
Agenda
• Process-tracing: logic and use
Moving beyond correlation: process
tracing
• Process Tracing is a method for assessing
whether C is a cause of E that moves beyond
the logic of covariation.
• Instead, it is based on looking for clues within
a single case to determine whether the facts
are consistent with the process through which
C causes E
C → S1 → S2 → S3 → S4 ….. → E
How to process trace?
Examining a single instance in which the outcome
did or did not occur and trying to explain why.
1. We wonder: Does C cause E?
2. We see that E is present and that C is present in
a case.
– But this doesn’t tell us that C caused E in that case.
How could we figure that out?
3. Think about the causal logic through which C
would have caused E if C did cause E.
4. Now investigate the case to see whether that
causal logic in fact unfolded within the case.
What causes civil war?
• Ethnic tensions?
• Poverty?
• Natural resources (diamonds, oil)?
• Weak state?
The problem: Often all 3 are present →
correlations won’t tell you which one is the
cause.
What caused DRC civil war?
• Precious natural resources?
Causal logic(s):
Presence of natural resources → rising tensions over disposition
of profits and grievances against those who control the
resources → motivates uprising by dispossessed groups who
seek to take the resources → occurrence of civil war
Presence of natural resources → increased frequency of rebel
groups taking over or looting resources to finance and arm
themselves → stronger rebel groups → decreased ability of
state to quickly crush them → occurrence of civil war
What caused DRC civil war?
• Precious natural resources?
Causal logic(s):
Presence of natural resources → rising tensions over disposition
of profits and grievances against those who control the
resources → motivates uprising by dispossessed groups who
seek to take the resources → occurrence of civil war
Presence of natural resources → increased frequency of rebel
groups taking over or looting resources to finance and arm
themselves → stronger rebel groups → decreased ability of state
to quickly crush them → occurrence of civil war
What caused DRC civil war?
• Precious natural resources?
Causal logic(s):
Presence of natural resources → rising tensions over disposition
of profits and rising grievances against those who control the
resources → motivates uprising by dispossessed groups who
seek to take the resources → occurrence of civil war
Presence of natural resources → increased frequency of rebel
groups taking over or looting resources to finance and arm
themselves → stronger rebel groups → decreased ability of state
to quickly crush them → occurrence of civil war
What caused DRC civil war?
• Precious natural resources?
Causal logic(s):
Presence of natural resources → rising tensions over disposition
of profits and rising grievances against those who control the
resources → motivates uprising by dispossessed groups who
seek to take the resources → occurrence of civil war
Presence of natural resources → increased frequency of rebel
groups taking over or looting resources to finance and arm
themselves → stronger rebel groups → decreased ability of state
to quickly crush them → occurrence of civil war
What caused DRC civil war?
• Precious natural resources?
Causal logic(s):
Presence of natural resources → rising tensions over disposition
of profits and rising grievances against those who control the
resources → motivates uprising by dispossessed groups who
seek to take the resources → occurrence of civil war
Presence of natural resources → increased frequency of rebel
groups taking over or looting resources to finance and arm
themselves → stronger rebel groups → decreased ability of state
to quickly crush them → occurrence of civil war
What caused DRC civil war?
• Ethnic tensions?
Causal logic(s):
Historical ethnic hatreds → desire by each
group to dominate or extinguish the other →
increase in violence by each side designed to
dominate/extinguish other group → spirals
into all-out war
What caused DRC civil war?
• Ethnic tensions?
Causal logic(s):
Historical ethnic hatreds → desire by each group
to dominate or extinguish the other → increase
in violence by each side designed to
dominate/extinguish other group → spirals into
all-out war
Process tracing tests
Hoop test
• A test that a hypothesis has to pass for us to believe it
(a “hoop” the theory has to jump through)
– If hoop test failed: the hypothesis is greatly weakened
– If hoop test passed: the hypothesis survives, but doesn’t
mean it’s true
Smoking gun test
• A test that can point strongly to the correctness of a
hypothesis
– If smoking gun test failed: the hypothesis survives
– If smoking gun test passed: the hypothesis is very likely
true
What happens when tests are passed or
failed?
H fails H passes
Hoop test H greatly
weakened
H slightly
strengthened
Smoking gun
test
H slightly
weakened
H greatly
strengthened
Asymmetric outcomes
Process tracing tests (cont.)
• Straw in the wind test
– Passing = hypothesis is relevant but not confirmed
– Failing = hypothesis is not eliminated but slightly
weakened
• Doubly decisive test
– Passing = hypothesis is confirmed and others are
eliminated
– Failing = hypothesis is eliminated
Why didn’t Obama break up the big
banks?
A. Because he didn’t want to alienate rich Wall
Street donors
B. Because Republican opposition made it
impossible
What clues could we look for?
1. Did Obama get a lot of campaign money from
Wall Street?
Hoop test for A
If no, A is probably wrong
If yes, A survives (but still could be wrong)
Why didn’t Obama break up the big
banks?
A. Because he didn’t want to alienate rich Wall
Street donors
B. Because Republican opposition made it
impossible
What clues could we look for?
2. Were Republicans against breaking up the banks?
Hoop test for B
If no, B is probably wrong
If yes, B survives (but still could be wrong)
Why didn’t Obama break up the big
banks?
A. Because he didn’t want to alienate rich Wall
Street donors
B. Because Republican opposition made it
impossible
What clues could we look for?
3. Did the White House propose breakup and lobby
the Senate Finance committee to get it to happen?
Smoking gun test for B
If no, B could still be right (maybe he didn’t bother
proposing because he knew it wouldn’t pass)
If yes, B is very likely right (hard to explain without B)
Why didn’t Obama break up the big
banks?
A. Because he didn’t want to alienate rich Wall
Street donors
B. Because Republican opposition made it
impossible
What clues could we look for?
4. Did the White House decide against proposing a
breakup shortly after meeting with Wall Street
donors?
Smoking gun test for A
If no, A could still be right.
If yes, A is very likely right (hard to explain without
A).
Process tracing: advantages
• Yields in-depth knowledge of context
• Opportunity for discovery
– Immersion in a case often suggests causal claims
we hadn’t thought of before
– Not just testing theories, but developing new
theories
• Avoids troubles with correlation
– Studying causal processes → less chance to be
fooled by spuriousness, reverse causation,
randomness