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Independent Sample T-test
• Classical design used in psychology/medicine
• N subjects are randomly assigned to two
groups (Control * Treatment).
• After treatment, the individuals are measured
on the dependent variable.
• A test of differences in means between groups
provides evidence for the treatment's effect.
Measures of Variation
• A lot of statistical techniques (using interval data)
use measures of variation in some manner
• What is the difference between a standard
deviation, the standard error of the mean, and
the standard error of the difference between
means? Or How are they related? Look in the
glossary to help you answer these questions?
Using Measures of Variation
• Leaned how to measure variation in data, i.e., variance,
standard deviation (Ch.4)
• Used the normal curve & SD to calculate z-scores and
probabilities (Ch.5)
• Used the normal curve & the z-score & the SE of the
mean to calculate confidence intervals (Ch.6)
• Used the concept of the confidence interval and the
standard error of the differences between means to
calculate the t-test (Ch.7)
• Use the sum of squares Σ(X – Mean)2 [sum of the
squared differences from the mean] in ANOVA
Null Hypothesis
• The two groups come from the same
population or that the two means are equal
• μ 1 = μ2
Levels of Significance
• What does an α = .05 level of significance
mean?
• We decide to reject the null if the
probability is very small (5% or less) that
the sample difference is a product of
sampling error.
• The observed difference is outside the
95% confidence interval of the difference
Choosing a Level of Significance
• Convention
• Minimize type I error – Reject null
hypothesis when the null is true
• Minimize type II error – fail to reject null
when the null is false
• Making alpha smaller reduces the
likelihood of making a type I error
• Making alpha larger reduces the
probability of a type II error
Independent Sample T-test
Formula
t=
X1  X 2
s X1  X 2
 N1s1  N 2 s2
 
 N1  N 2  2
2
s x1  x2
2
 N1  N 2 


 N N 
 1 2 
Assumptions of the t-test
• 1. All observations must be independent of each other (random
sample should do this)
• 2. The dependent variable must be measured on an interval or ratio
scale
• 3. The dependent variable must be normally distributed in the
population (for each group being compared). (NORMALITY
ASSUMPTION) [this usually occurs when N is large and randomly
selected]
• 4. The distribution of the dependent variable for one of the groups
being compared must have the same variance as the distribution
for the other group being compared. (HOMOGENEITY OF
VARIANCE ASSUMPTION)
Don’t worry about these
assumptions to much, but
• Point 1: statistical tools are attempting to
quantify and analyze very complex
social/political phenomenon
• Point 2: For these test to be accurate they relay
on simplifying the world with many assumptions
that might not be true
• Point 3: social science researchers violate
these assumptions quite often, but try to be
honest about it
• Point 4: there are sometimes ways of testing
and adjusting for violations
SPSS & the Independent Sample T-Test
Group Statistics
VAR00001
VAR00002
1.00
2.00
N
10
10
Mean
102.0000
98.0000
Std. Error
Mean
10.03328
9.63789
Std. Deviation
31.72801
30.47768
Independent Samples Test
Levene's Test for
Equality of Variances
F
VAR00001
Equal variances
ass umed
Equal variances
not as sumed
.073
Sig.
.789
t-tes t for Equality of Means
t
df
Sig. (2-tailed)
Mean
Difference
Std. Error
Difference
95% Confidence
Interval of the
Difference
Lower
Upper
.288
18
.777
4.00000
13.91242 -25.22892
33.22892
.288
17.971
.777
4.00000
13.91242 -25.23230
33.23230
Crime and Support for Democracy
Kenneth E. Fernandez
Department of Political Science
University of Nevada, Las Vegas
Michele Kuenzi
Department of Political Science
University of Nevada, Las Vegas
Research Question
Does crime influence how citizens
evaluate democracies or influence their
level of support for democracy?
Why is this an Interesting Question?
• Scholars have noted that few studies, especially in
the field of political science, have examined crime
and its impact on society in a comparative manner
(Beirne 1997; Howard, et al. 2000).
• Current public opinion research suggests that the
issue of crime is of great concern to citizens
across the globe (Quann and Hung 2002)
• Many countries that have experienced recent
democratic reforms have also experienced
increasing crime rates (Bergman 2006).
What theories inform the study of
crime and democracy?
–Social Capital
–Rational Choice
–Modernization Theory
Social Capital Theories:
– Theory suggests that attitudes and feelings of
the masses regarding obligations within a
group, civic attachments, trust, and efficacy are
important determinants of democratic transition
and sustainability (Muller and Seligson 1994).
– Yet crime and violence is likely to reduce trust
and social capital (Lederman et al 2002).
Rational Choice:
– Citizens are treated as utility maximizing
consumers
– A political regime is expected to produce some
value or benefit to the consumer (Lane 1995).
– Regime support depends on how well citizens’
demands are met
– Thomas Hobbes argues that protection against
violence is the highest and most fundamental
human need and a citizen of the state has a
right to revoke its support and loyalty when the
state proves incapable of protecting its subjects.
The Paradox of Modernization theory:
– Modernization leads to increasing wealth,
leading to more literacy, education,
urbanization, leading to democratization
because citizens are less willing to put up with
oppressive, authoritarian behavior and more
willing to support democracy (Lipset 1959)
– But modernization may cause a breakdown in
traditional structures and values, an increase in
interaction, tension, and conflict. These social
changes then contribute to rising criminal
activity (Heiland and Shelley 1992).
Modernization Theory, Crime &
Democracy
– Consolidating both the political science and the
criminology/sociology literature on
modernization theory, we argue that socioeconomic conditions, as well as, crime and
public safety influence citizens’ support for
democracy.
Crime is Often Ignored as a Factor in Democratization
– Much of the prior research on the development of
democracy focuses on economic conditions (Arat 1988;
Epstein et al. 2006; Lipset 1959; Przeworski et al.
2000).
– In fact, Kugler and Feng describe the recent application
of modernization theory as positing that “economic
development is a sufficient, rather than a necessary,
condition for democratic transitions” (1999, 140).
– We argue that crime and public disorder may pose even
greater challenges to the legitimacy and effectiveness of
democratic institutions
Methodology: Macro or Micro Level
Analysis?
– Much of the research testing the modernization
theory uses a macrolevel approach utilizing the
nation-state at time t as the unit of analysis.
Aggregate national characteristics (i.e., per
capita GDP) are then used as predictors of
some measure of democracy.
– Yet Lipset (1959) posits that increases in wealth
and income leads to democratic transition
because it affects citizens’ values.
– We would like to examine this microlevel
statement.
Microlevel Analysis:
– An examination of citizen attitudes is
appropriate because the success of
democratic consolidation in these emerging
democracies is often linked to citizens’
support for democracy and perceptions of
government performance (Hiskey and Bowler
2005; Lagos 2001; Diamond 1999; Lipset
1959).
DATA:
• Afrobarometer (AB) and Latinbarometro (LB)
Survey Data
• The AB and LB together contain 33 countries (16
in Africa and 17 in Latin America).
Two Statistical Approaches
– Analysis of all countries pooled together (over
18,000 respondents in African and 13,000 in
Latin America
– Analysis of 4 cases
Case Selection:
– Initial Case - NIGERIA: Like many other
African countries, Nigeria experienced a
transition to democracy in the 1990s. We chose
Nigeria because crime is a very salient issue in
this country, and Nigeria has been well known
for mob justice or what has been called “jungle
justice”
– Most Different Systems Design: We
performed a cluster analysis to find a case in
the Afrobarometer data that was “most different”
to Nigeria in relation to three factors: crime,
democracy and per capita GDP.
Cluster Analysis:
The Euclidean distance between two cases is
calculated by finding the square root of the sum
of the squared differences between the two
cases for each of the three variables (crime
rate; per capita GDP; level of democracy):
x
i
 x j    yi  y j   zi  z j 
2
2
2
MALAWI: Nigeria has a per capita GDP nearly 3
times that of Malawi, but Nigeria has a
substantially higher reported victimization rate
(Nigeria had the highest reported attacks of the 14
African cases and Malawi had the lowest). Both
countries were given a score of 4 for political rights
and civil liberties by Freedom House in 2005.
CHILE & NICARAGUA: Both Chile and Nicaragua
have modest crime rates compared to the rest of
Central and South America, but differ greatly on
GDP and level of democracy. Chile has a per
capita GDP almost 7 times higher than Nicaragua
and Chile has a score of 1 for both political rights
and civil liberties while Nicaragua scored a 3 for
both.
THE 4 CASES: The results seem to make intuitive
sense. There is substantial variation in GDP
across cases, they vary in crime rates from low to
moderate to high levels of victimization, and levels
of political freedom and civil liberties varied from
the highest (score of 1) to moderate/low (score of
4).
Operationalization
Dependent Variables: Attitudes toward Democracy
Support for Democracy
• Which of these three statements is closest to your
own opinion?
• A: Democracy is preferable to any other kind of
government.
• B: In some circumstances, a non-democratic
government can be preferable.
• C: For someone like me, it doesn’t matter what kind
of government we have.
• Recoded so that the value on this variable is 1 if the
response was A, and 0 otherwise.
• Satisfaction with Democracy
• Overall, how satisfied are you with the way
democracy works in __________.? Are you:
• 0=Tanzania/Nigeria is not a democracy,
1=Not at all satisfied, 2=Not very satisfied,
3=Fairly satisfied, 4=Very satisfied.
Chile and Nicaragua:
• In general, would you say that you are very
satisfied, fairly satisfied, not very satisfied or
not at all satisfied with the way democracy
works in (country)? 4=Very satisfied - 1=Not
at all satisfied
Independent Variables
• Experience with Crime
• Comparative assessments of safety from
crime and violence
• Crime Performance
Control Variables
• Demographic variables: gender, level of
poverty, age, education
• Other variables: political engagement,
identification with the party in power, and
subjective assessments of satisfaction with
life and the economy and government
service delivery
TABLE 3: Attitudes Toward Democracy
AFRICA
Nigeria 2000
Nigeria 2001
Nigeria 2003
Malawi 1999
Malawi 2003
LATIN1996
AMERICA
Chile
Chile 2000
Chile 2003
Chile 2004
Nicaragua 1996
Nicaragua 2000
Nicaragua 2003
Nicaragua 2004
Support Democracy
81%
73
69
65
66
54%
55
52
62
64
68
59
50
Satisfaction with Democracy
85%
57
34
57
48
29%
34
34
44
25
17
34
23
Est. Method
Table 1: Pooled Afrobarometer and Latinbarometro Data
Support for
Satisfaction w/
Support for
Democracy
Democracy
Democracy
(AB Pooled Data)
(AB Pooled Data)
(LB Pooled Data)
Logit
0.200***
(0.036)
-0.284***
(0.061)
0.127***
(0.024)
Ordered Logit
0.267***
(0.038)
-0.145***
(0.043)
0.007
(0.020)
0.078***
(0.028)
0.180***
(0.030)
0.050**
(0.026)
0.374***
(0.036)
0.037
(0.033)
-0.041
(0.040)
0.251***
(0.061)
0.059
(0.041)
Education
0.023
(0.022)
-0.090***
(0.022)
Poor
-0.010
(0.062)
-0.087**
(0.045)
-0.118***
(0.048)
-0.047
(0.049)
0.004*
(0.002)
0.005***
(0.002)
Feel Safer
Victim of Crime
Discuss Politics
Radio-News
Service Delivery
Economy
Quality of Life
Female
Age
Cons
# obs
Pseudo R2
LR chi2
Prob > chi2
Ordered Logit
0.325***
(0.076)
-0.121**
(0.059)
0.051
(0.032)
0.033
(0.020)
0.033*
(0.013)
0.030
(0.030)
0.163***
(0.030)
-0.016
(0.050)
0.366***
(0.055)
0.106
(0.068)
0.229***
(0.054)
0.035**
(0.014)
-0.001
(0.009)
0.032
(0.053)
0.041
(0.063)
-0.067
(0.050)
-0.084
(0.049)
0.011***
(0.003)
0.004
(0.002)
-1.751***
(0.407)
-0.828***
(0.315)
18,476
0.034
235.10
0.000
Logit
0.146*
(0.084)
0.023
(0.056)
0.199***
(0.053)
Satisfaction w/
Democracy
(LB Pooled Data)
18,695
0.061
904.72
0.000
13,826
.0214
153.90
0.000
14,125
.0435
335.45
0.0000
Est. Method
TABLE 4: ATTITUDES TOWARD DEMOCRACY
Model 1
Model 2
Support for
Support for
Satisfaction w/
Satisfaction w/
Democracy
Democracy
Democracy
Democracy
(Nigeria)
(Malawi)
(Nigeria)
(Malawi)
Logit
Logit
Ordered Logit
Ordered Logit
0.236***
(0.044)
-0.009
(0.051)
0.385***
(0.038)
0.078*
(0.045)
-0.499***
(0.113)
-0.627**
(0.261)
-0.069
(0.101)
0.182
(0.228)
0.058
(0.039)
0.054
(0.049)
0.060*
(0.033)
-0.060
(0.041)
0.144***
(0.046)
-0.056
(0.051)
0.002
(0.041)
0.163***
(0.044)
0.101**
(0.044)
0.166***
(0.048)
0.179***
(0.038)
0.488***
(0.044)
0.081*
(0.044)
0.085
(0.070)
0.428***
(0.038)
0.240***
(0.059)
-0.112***
(0.046)
-0.005
(0.073)
0.173***
(0.040)
0.014
(0.062)
Education
-0.018
(0.025)
0.115**
(0.051)
-0.049**
(0.021)
-0.173***
(0.041)
Poor
-0.037
(0.061)
-0.125
(0.108)
-0.157***
(0.051)
-.343***
(0.091)
Female
-0.052
(0.099)
-0.412***
(0.144)
-0.019
(0.084)
-0.449***
(0.122)
Age
0.002
(0.004)
0.005
(0.005)
-0.000
(0.003)
0.008*
(0.004)
Cons
-0.440
(0.326)
0.146
(0.494)
2,261
0.036
99.63
0.000
1,009
0.032
41.26
0.000
2,270
0.104
627.93
0.000
1,019
0.088
258.38
0.000
Feel Safer
Victim of
Crime
Discuss
Politics
Radio-News
Service
Delivery
Economy
Quality of Life
# obs
Pseudo R2
LR chi2
Prob > chi2
TABLE 5: ATTITUDES TOWARD DEMOCRACY II
Model 3
Model 4
Support for
Support for
Satisfaction w/
Satisfaction w/
Democracy
Democracy
Democracy
Democracy
(Nigeria)
(Malawi)
(Nigeria)
(Malawi)
Est. Method
Logit
Logit
0.197***
(0.056)
0.18
(0.78)
0.531***
(0.048)
0.324***
(0.069)
Victim of Crime
-0.522***
(0.112)
-0.658***
(0.258)
-0.114
(0.101)
0.248
(0.226)
Discuss Politics
0.064*
(0.038)
0.060
(0.049)
0.056*
(0.033)
-0.053
(0.042)
Radio-News
0.144***
(0.046)
-0.057
(0.051)
0.008
(0.040)
0.156***
(0.045)
Service Delivery
0.127***
(0.043)
0.157***
(0.048)
0.209***
(0.037)
0.481***
(0.044)
0.089**
(0.043)
0.094
(0.070)
0.421***
(0.038)
0.240***
(0.060)
-0.120***
(0.046)
-0.021
(0.073)
0.145***
(0.040)
0.004
(0.062)
Education
-0.010
(0.025)
0.114**
(0.051)
-0.045**
(0.021)
-0.153***
(0.042)
Poor
-0.064
(0.060)
-0.144
(0.109)
-0.215***
(0.052)
-0.358***
(0.091)
Female
-0.047
(0.098)
-0.417***
(0.144)
-0.048
(0.083)
-0.470***
(0.123)
Age
0.003
(0.004)
0.006
(0.005)
0.002
(0.003)
0.009**
(0.005)
Cons
-0.270
(0.323)
2,266
0.029
82.51
0.000
0.143
(0.505)
1,008
0.033
42.29
0.00
2,278
0.109
660.51
0.000
1,014
0.094
273.63
0.000
Govt. Reducing
Crime
Economy
Quality of Life
# obs
Pseudo R2
LR chi2
Prob > chi2
Ordered Logit
Ordered Logit
TABLE 6: ATTITUDES TOWARD DEMOCRACY I
Model 5
Model 6
Support
Support Democracy
Satisfaction w/
Satisfaction w/
Democracy
(Nicaragua)
Democracy
Democracy
(Chile)
(Chile)
(Nicaragua)
Est. Method
Logit
Logit
0.6105***
(0.1449)
0.3072**
(0.1441)
0.7250***
(0.1254)
0.5156***
(0.1358)
0.0789
(0.1843)
-0.3046
(0.1879)
-0.0113
(0.1725)
0.1028
(0.1651)
0.3767***
(0.1111)
0.3704***
(0.0987)
0.0182
(0.1255)
0.0377
(0.0863)
-0.047
(0.0545)
-0.04405
(0.066903)
0.0299
(0.0522)
-0.0222
(0.0570)
-0.015
(0.0617)
-0.123**
(0.0535)
0.1971**
(0.0648)
0.1420***
(0.0524)
0.3088**
(0.1231)
-0.0029
(0.1174)
0.6488***
(0.1303)
0.3951***
(0.0940)
0.2837**
(0.1201)
0.0178
(0.1067)
0.4262***
(0.1164)
0.2818***
(0.1007)
Education
0.0387
(0.0295)
-0.0118
(0.0228)
0.0491*
(0.0294)
0.0045
(0.0193)
Poverty
0.1861
(0.1395)
-0.0366
(0.1061)
0.1574
(0.1480)
0.004932
(0.0889)
Female
0.0174
(0.180683)
-0.2390
(0.1811)
-0.089
(0.1734)
-0.65567***
(0.1640)
0.0111*
(0.0063)
0.0120*
(0.0064)
0.0180**
(0.0061)
0.011286*
(0.0061)
-4.5247***
(0.7308)
1023
0.1020
85.54
0.0000
-0.6752
(0.6975)
613
0.0478
30.44
0.0014
1040
0.1292
165.28
0.0000
652
0.0585
81.41
0.0000
Feel Safer
Victim of Crime
Discuss Politics
TV-News
Service Delivery
Economy
Quality of Life
Age
Cons
# obs
Pseudo R2
LR chi2
Prob > chi2
Ordered Logit
Ordered Logit
TABLE 7: ATTITUDES TOWARD DEMOCRACY II
Model 7
Model 8
Support
Support Democracy
Satisfaction with
Satisfaction with
Democracy
(Nicaragua)
Democracy
Democracy
(Chile)
(Chile)
(Nicaragua)
Est. Method
Logit
Logit
0.3019**
(0.1336)
0.3320***
(0.1180)
0.4495***
(0.1365)
0.3620***
(0.1107)
-0.0176
(0.1896)
-0.2076
(0.1929)
-0.0202
(0.1776)
0.1336
(0.1672)
0.4759***
(0.1216)
0.3663***
(0.1002)
0.0278
(0.1278)
0.0183
(0.0856)
-0.0327
(0.0568)
-0.0232
(0.0679)
0.0366
(0.0507)
0.0227
(0.0581)
0.0182
(0.0648)
-0.1179**
(0.0561)
0.2107***
(0.0662)
0.1414***
(0.0526)
0.4059***
(0.1296)
0.0094
(0.1179)
0.7059***
(0.1353)
0.4070***
(0.0937)
0.2248*
(0.1226)
-0.0108
(0.1104)
0.4065***
(0.1146)
0.2658***
(0.1028)
Education
0.0384
(0.0309)
-0.0092
(0.0234)
0.0484
(0.0305)
0.0066
(0.0195)
Poverty
0.1871
(0.1437)
-0.0438
(0.1099)
0.2208
(0.1464)
0.0152
(0.0908)
Female
0.0260
(0.1852)
-0.2137
(0.1839)
-0.0736
(0.1750)
-0.6451
(0.1668)
Age
0.0080
(0.0062)
0.0143**
(0.0065)
0.0149***
(0.0057)
0.0114*
(0.0064)
-4.1139***
(0.7574)
1000
0.0903
74.65
0.0000
-0.9637
(0.6937)
604
0.0538
32.55
0.0006
1018
0.1159
133.45
0.0000
640
0.0548
73.55
0.0000
War on Crime
Victim of Crime
Discuss Politics
TV-News
Service Delivery
Economy
Quality of Life
Cons
# obs
Pseudo R2
LR chi2
Prob > chi2
Ordered Logit
Ordered Logit
Results
Attitudes toward Democracy
Feeling Safe
• Nigerians who report feeling better off in
terms of safety from crime and violence are
significantly more likely to:
– Support democracy
– Be satisfied with the way democracy is working
• Malawians who report feeling better
off in terms of safety from crime and
violence are significantly more likely
to:
– Be satisfied with the way democracy is
working
• Nicaraguans and Chileans who felt
the country was getting safer were
also more likely to:
– Support democracy
– Be satisfied with the way democracy is
working
Government Performance in Crime
Reduction
• Results generally stronger
Crime Victimization
• Nigerians and Malawians who report a
higher number of experiences with crime
victimization have significantly lower levels
of support for democracy.
• There appears to be no relationship
between crime victimization and attitudes
toward democracy in the Chile and
Nicaragua countries.
Conclusion and Implications
• Perceptions of safety and government
performance in the area of crime
affect attitudes toward democracy.
• Crime victimization generally does not
appear related to satisfaction with
democracy.
• Issue of crime likely to affect the
consolidation of democracy
• Future research should:
–Examine other regions
–Assess whether there is a threshold
effect
–Examine potential intervening
variables