Title: Socio-Economic%20Antecedents%20of%20Transnational%20Terrorism:%20Causal%20Graphs
1Socio-Economic Antecedents of Transnational
Terrorism Causal Graphs
AGEC689 Terrorism and Homeland Security
David A. Bessler
2Bio-Security and Terrorism
- All of the events studied, thus far in this
course have been introduced (we think) by chance.
FMD, BSE, and next lecture AI are not
intentionally introduced into our food chain. - However, it may be the case that such maladies
could be intentionally introduced to cause harm
to the local population.
3What is Transnational Terrorism
- Transnational terrorism is a premeditated
threatened or actual use of force or violence to
attain a political goal through fear, coercion,
or intimidation and when its ramifications
transcend national boundaries through the
nationality of the perpetrators and/or human or
institutional victims, location of the incident,
or mechanics of its resolution (Mickolus et al.
1989).
4Research Question
- Do social, economic, and political factors
influence the environment conducive to terrorist
activities? - If so, how?
5Counter-Terrorism Strategies
- Strategies and terrorism formats
- Strategies focusing on terrorism of certain
format (mental detection) - Strategies less sensitive to terrorism format
(international sanctions, financial aid,
education assistance) - Protective vs. responsive strategies
- If protective strategies is more desirable to
thwart terrorism, then we need to think about
factors encouraging/discouraging terrorism
participation.
6Does Poverty Breed Terrorism?
- Some say Yes
- Alesina et al. (1996) suggest that poor economic
conditions increase the probability of political
coups. - Hess and Orphandies (2001) show that the
frequency of war is greater following recessions
than economic growth. - Blomberg and Hess (2002) suggest that economic
recessions increase the prob. of
internal/external conflicts - Blomberg, Hess and Weerapana (2004) find that
economic recessions increases the probability of
terrorist activities in democratic high-income
countries. - Li and Schaub (2004) find that economic
development decreases the number of international
terrorist incidents. - Fearon and Laitin (2003) conclude that poverty
has a significant positive effect on violent
domestic conflicts. - Some say No
- Piazza (2006) finds no significant relationship
between terrorism and income equity, per capita
GDP growth, unemployment, and so forth - Krueger and Maleckova (2003) finds no statistical
relationship between involvement in terrorism
events and economic activity. - Abadie (2006) finds no significant relationship
between risk of terrorism and economic variables.
- Krueger and Laitin (2003) suggest that poor
countries do not generate more terrorism than
rich countries with similar levels of civil
liberties.
7Do Other Economic Conditions Matter?
- Political freedom?
- Abadie (2006) finds a countries with intermediate
levels of political freedom are more prone to
terrorism than countries with high or low levels
of political freedom - Li (2005) shows that democratic participation
reduces transnational terrorism. - Education?
- Stern (2000) attributes involvement in terrorist
acts to lack of adequate education. - Others like trade, income equality?
- Li and Schaub (2004) find that trade, foreign
direct investment, and portfolio of investment
have no direct positive effect on the number of
terrorist events. - Muller and Seligson (1990) and London and
Robinson (1989) show that income inequality is a
significant predictor of political violence.
8What is Our Specific Mission
- Separate the impacts of socio-economic and
political factors on - Likelihood of terrorism participation
- Number of terrorism participation at country
level - Investigate the relationships of terrorism
participation and - Income
- Education
- Poverty
- Freedom
- Openness to trade
- Concentration of Wealth
9Data Sources
- The chronological data on transnational terrorism
events was obtained from Dr. Edward Mickolus
(Vinyard Software Inc.), including - incident date, incidents country of origin,
location of incident, up to three nationalities
of victims, and up to three nationalities of
perpetrators. - Socio-economic and political variables
- World Bank data base
- CIA world factbook
- Various National Statistics Services
- Heritage Foundation
10Dependent Variable
- The dependent variable is annual counts of
terrorism events by country and year in which
citizens of a particular country were documented
as perpetrators. - The annual count of terrorism events for
Philippines in 2000 is seven, which means that
the Philippine nationals were documented as
perpetrators for seven transnational terrorism
incidents in 2000. - The original chronological data documents up to
three nationalities of perpetrators for each
terrorism incident. - On March 15, 1982 three Salvadorans, two
Nicaraguans, one Chilean and others were arrested
for intending to kidnap an unidentified American
diplomat. This incident increases the annual
count of terrorism events by one for Salvador,
Nicaragua, and Chile each. - Documented with known nationalities vs. unknown
nationalities - Unknown either the perpetrators or their
nationalities were not traceable. - Counts vs. Incidents
11Independent Variables
Name Name Definition Mean SD
Income/Wealth measures Income/Wealth measures Income/Wealth measures
GDP GDP per capita (1,000) 6,737 8,880
GINI GINI index (0perfectly inequity 1perfectly equity) 0.40 0.11
PV1 population ratio living under 1/day 0.11 0.15
PV12 population ratio living on 1 to 2/day 0.25 0.15
Education Trade and Economic freedom measures Education Trade and Economic freedom measures Education Trade and Economic freedom measures
Literacy population ratio who can read and write 0.82 0.20
Trade (ImportsExports)/GDP 0.67 0.52
Freedom economic freedom (1highest 5lowest) 3.01 0.64
12Inference on Causal Flows
- Oftentimes we are uncertain about which
- variables are causal in a modeling effort.
- Theory may tell us what our fundamental
- causal variables are in a controlled system.
- It is common that our data may not be
- collected in a controlled environment.
13Use of Subject Matter Theory
- Theory may be a good source of information
about - direction of causal flow among variables.
However, - theory usually invokes the ceteris paribus
condition - to achieve results.
Data are often observational (non-experimental) an
d thus the ceteris paribus condition may
not hold. We may not ever know if it holds
because of unknown variables operating on our
system.
14Inference on Causal Flows
- Oftentimes we are uncertain about which
- variables are causal in a modeling effort.
- Theory may tell us what our fundamental
- causal variables are in a controlled system.
- It is common that our data may not be
- collected in a controlled environment.
15Use of Subject Matter Theory
- Theory may be a good source of information
about - direction of causal flow among variables.
However, - theory usually invokes the ceteris paribus
condition - to achieve results.
Data are often observational (non-experimental) an
d thus the ceteris paribus condition may
not hold. We may not ever know if it holds
because of unknown variables operating on our
system.
16Use of Subject Matter Theory
- Theory may be a good source of information
about - direction of causal flow among variables.
However, - theory usually invokes the ceteris paribus
condition - to achieve results.
Data are often observational (non-experimental) an
d thus the ceteris paribus condition may
not hold. We may not ever know if it holds
because of unknown variables operating on our
system.
17Experimental Methods
- If we do not know the "true" system, but have an
idea that one or more variables operate on that
system, then experimental methods can yield
appropriate results.
- Experimental methods work because they use
randomization, random assignment of subjects to
alternative treatments, to account for any
additional variation associated with the unknown
variables on the system.
18Observational Data
- In the case where no experimental control is
used in the generation of our data, such data are
said to be observational (non-experimental).
19Causal Models Are Well-Represented By Directed
Graphs
- One reason for studying causal models,
represented here as X ? Y, is to predict the
consequences of changing the effect variable (Y)
by changing the cause variable (X). The
possibility of manipulating Y by way of
manipulating X is at the heart of causation.
Causation seems connected to intervention and
manipulation one can use causes to wiggle
their effects. -- Hausman (1998, page 7)
20Directed Acyclic Graphs
- Pictures summarizing the causal flow among
variables -- there are no cycles.
- Inference on causation is informed by asymmetries
among causal chains, causal forks, and causal
inverted forks.
21A Causal Fork
- For three variables X, Y, and Z, we illustrate
- X causes Y and Z as
Here the unconditional association between Y and
Z is non-zero, but the conditional association
between Y and Z, given knowledge of the common
cause X, is zero.
Knowledge of a common cause screens off
association between its joint effects.
22An Example of a Causal Fork
- X is the event, the student doesnt learn the
material - in Econ 629.
- Y is the event, the student receives a grade of
D in - Econ 629.
- Z is the event, the student fails the PhD prelim
in - Economic Theory.
Grades are helpful in forecasting whether a
student passes his/her prelims P (Z Y) gt P
(Z)
If we add the information on whether he/she
understands the material, the contribution of
grade disappears (we do not know candidates name
when we mark his prelim) P (Z Y, X) P (Z X)
23An Inverted Fork
- Illustrate X and Z cause Y as
- Here the unconditional association between X
- and Z is zero, but the conditional
association - between X and Z, given the common effect Y
is - non-zero
Knowledge of a common effect does not screen off
the association between its joint causes.
24The Causal Inverted Fork An Example
- Let Y be the event that my daughters cell-phone
wont - work
- Let X be the event that she did not pay her
phone bill - Let Z be the event that her battery is dead
- Paying the phone bill and the battery being dead
are - independent P(XZ) P(X).
- Given I know her battery is dead (she remembers
that she - did not charge it for a week) gives some
information - about bill status P(XY,Z) lt P (XY).
- (although I dont know her bill status for sure).
- X ? Y ? Z
25The Literature on Such Causal Structures Has Been
Advanced in the Last Decade Under the Label of
Artificial Intelligence
- Pearl, Causality, Cambridge Press, 2000
- Spirtes, Glymour and Scheines, Causation,
- Prediction and Search, MIT Press, 2000
- Glymour and Cooper, editors, Computation,
- Causation and Discovery, MIT Press, 1999
26Causal Inference Engine
- PC Algorithm
- 1. Form a complete undirected graph connecting
every variable with all other variables.
2. Remove edges through tests of zero
correlation and partial correlation.
3. Direct edges which remain after all possible
tests of conditional correlation.
4. Use screening-off characteristics to
accomplish edge direction.
27Assumptions(for PC algorithm on observational
data to give same causal model as a random
assignment experiment)
- 1. Causal Sufficiency
- 2. Causal Markov Condition
- 3. Faithfulness
- 4. Normality
28Causal Sufficiency
- No two included variables are caused by a
- common omitted variable.
No hidden variables that cause two included
variables.
Z
29Causal Markov Condition
- The data on our variables are
- generated by a Markov property,
- which says we need only condition
- on parents
P(W, X, Y, Z) P(W) P(XW) P(Y) P(ZX,Y)
30Faithfulness
- There are no cancellations of parameters.
A b1 B b3 C C b2 B
It is not the case that -b2 b3 b1
Deep parameters b1, b2 and b3 do not form
combinations that cancel each other.
31Figure 1. Graphical Representation on Eight
Variables Related to Terrorism Events in
Countries and Economic and Political
Characteristics. Note the numerical values
embedded in the lower right hand corner of each
variable rectangle are the mean values of that
variable over the sample. The numerical values
embedded in each arrow represent the estimated
coefficient from a regression of the effect
variable on the cause variable, taking into
account the backdoor paths in that regression.
32Cautions on Interpretations of the Results
- The dataset was constructed using a limited
amount of best available information and involved
extrapolation of socio-economic estimates over
the periods for which data was not available.
Caution is warranted for interpretation of the
results. - The findings should be interpreted as no more
than a preliminary support of the idea that
socioeconomic factors may play a role in
encouraging/discouraging terrorist behavior. - Further studies based on either more complete
records or on alternative approaches, which would
avoid reliance on observational data, are
necessary to fully understand the linkage between
socioeconomic factors and participation in
transnational terrorism acts.