Borrowing Support for War:
The Effect of War Finance on Public Attitudes toward Conflict
Online Appendix
I. Experimental Conditions for Main Experiments in the US and UK
Respondents were randomly assigned into one of 6 groups as follows:
Method of finance
Type of
intervention
Interests
Values
Hybrid
Baseline
Taxes
1
3
5
2
4
6
Group 1. Interests, Baseline
Suppose a foreign government attacked a key ally of the United States. In response, the United
States decides to launch a military operation to help defend the ally.
The United States would finance the conflict in part through the existing budget and in part
through debt.
To what extent would you support or oppose this war?
-
Strongly support the war
Somewhat support the war
Slightly support the war
Neither support nor oppose the war
Slightly oppose the war
Somewhat oppose the war
Strongly support the war
Group 2. Interests, Taxes
Suppose a foreign government attacked a key ally of the United States. In response, the United
States decides to launch a military operation to help defend the ally.
The United States would finance the conflict in part through the existing budget, in part through
debt, and in part through a war tax.
To what extent would you support or oppose this war?
Group 3. Values, Baseline
Suppose a foreign government were engaged in ethnic cleansing within its borders. In response,
the United States decides to launch a military operation to provide humanitarian assistance.
1
The United States would finance the conflict in part through the existing budget and in part
through debt.
To what extent would you support or oppose this war?
Group 4. Values, Tax
Suppose a foreign government were engaged in ethnic cleansing within its borders. In response,
the United States decides to launch a military operation to provide humanitarian assistance.
The United States would finance the conflict in part through the existing budget, in part through
debt, and in part through a war tax.
To what extent would you support or oppose this war?
Group 5. Hybrid, Baseline
Suppose a foreign government began exporting weapons of mass destruction to adversaries of
the United States. In response, the United States decides to launch a military operation to help
overthrow the government and install a democratic regime.
The United States would finance the conflict in part through the existing budget and in part
through debt.
To what extent would you support or oppose this war?
Group 6. Hybrid, Tax
Suppose a foreign government began exporting weapons of mass destruction to adversaries of
the United States. In response, the United States decides to launch a military operation to help
overthrow the government and install a democratic regime.
The United States would finance the conflict in part through the existing budget, in part through
debt, and in part through a war tax.
To what extent would you support or oppose this war?
NB: For replication in the UK, “United States” was replaced with “United Kingdom” in
every treatment.
2
II. Data for the Figures in the Main Text
1. Support for War by Method of War Finance in the US and UK
US
UK
Baseline
Taxes
Difference
Baseline
Taxes
Difference
46.1
36.3
46.7
34.5
-9.8***
-12.2***
Support
(1.7)
(1.7)
(1.8)
(1.7)
(2.4)
(2.5)
(%)
1254
1246
1053
1069
2. Support for War by Method of War Finance, by Type of War
US
UK
Baseline
Taxes
Difference
Baseline
Taxes
Difference
51.7
43.6
46.6
37.5
-8.1**
-9.0**
(2.9)
(2.9)
(3.1)
(3.1)
Interests
(4.1)
(4.3)
442
421
366
352
44.2
35.3
46.1
34.5
-8.9**
-11.5***
(3.0)
(3.0)
(3.3)
(2.9)
Hybrid
(4.2)
(4.4)
397
430
341
375
41.4
29.9
47.4
31.3
-11.5***
-16.1***
(2.9)
(2.6)
(3.15)
(2.92)
Values
(3.9)
(4.3)
415
395
346
342
3. Support for War by Method of War Finance, by Party ID
US
UK
Baseline Taxes
Difference
Baseline
Taxes
Difference
43.5
28.0
45.2
34.4
-15.5***
-10.8**
(2.9)
(2.5)
(3.2)
(3.2)
Democrat
Labour
(3.8)
(4.5)
469
453
332
321
Independent
45.7
(3.0)
379
36.9
(3.0)
408
-8.8**
(4.2)
Liberal
Democrat
59.1
(5.1)
109
38.5
(5.1)
116
-20.6***
(7.2)
59.9
50.1
56.0
39.4
-9.8**
-16.6***
(3.4)
(3.5)
(3.4)
(3.2)
Conservative
(4.9)
(4.7)
290
294
272
300
4. Support for War by Type of Burden (MTurk)
No Cost
Debt
Taxes
Casualties
Difference
Difference
Baseline
Taxes-Debt Casualties-Debt
60.6
58.7
44.6
39.2
-14.1**
-19.4***
(Interests
(0.05)
(0.05)
(0.05)
(0.05)
(6.9)
(6.9)
Scenario)
104
104
101
102
5. Mean Estimate of the Cost of the War (MTurk)
Baseline
Debt
Taxes
Casualties
3.42
3.44
3.46
3.53
Estimated Cost of War
(0.10)
(0.11)
(0.11)
(0.11)
(Interests Scenario)
104
104
101
102
NB: Cells show % support followed by standard errors in parenthesis and sample sizes. Difference indicates test for
differences in means. *** p < 0.01; ** p <0.05; * p <0.1. All tests are two-tailed. Figures are rounded.
Republican
3
III. Logit Estimation of Support for War (Interaction terms between party ID and method of
finance not significant.)
United States
(1)
-0.52***
(0.2)
0.09***
(0.03)
0.03
(0.04)
Tax Treatment
Party ID (7-Republican)
Tax treatment x Party ID
Female
Education
Income
Age
Constant
-0.5
(0.14)
2500
N
(2)
-0.51**
(0.23)
0.11***
(0.04)
0.02
(0.05)
-0.42***
(0.11)
0.04
(0.04)
0.09***
(0.02)
0.0
(0.0)
-3.05
(7.25)
2073
United Kingdom
(3)
-4.5**
(0.19)
0.44**
(0.19)
0.56
(4)
-0.56***
(0.21)
Conservative
0.29
(0.23)
Liberal Democrats
0.39
(0.29)
Tax Treatment x Conservative
-0.11
(0.32)
Tax Treatment x Liberal Democrats
-0.09
(0.4)
Female
-0.63***
(0.14)
Education
0.0
(0.02)
Income
0.04**
(0.02)
Age
0.01
(0.01)
Constant
-0.19
-10.03
(0.13)
(9.03)
N
1450
1114
NB: DV is support for war. Robust SE in parenthesis. Significance: *** p < 0.01; ** p <0.05; * p <0.1.
Labour is the reference category for Party ID in the UK.
Tax Treatment
4
IV. Experimental Conditions for Follow-Up Test (Robustness Check)
Condition 1: Baseline
Suppose a foreign government attacked a key ally of the United States. In response, the United
States decides to launch a military operation to help defend the ally.
The United States would finance the conflict in part through the existing budget and in part
through debt.
To what extent would you support or oppose this war?
Condition 2: Taxes
Suppose a foreign government attacked a key ally of the United States. In response, the United
States decides to launch a military operation to help defend the ally.
The United States would finance the conflict in part through the existing budget, in part through
debt, and in part through a war tax.
To what extent would you support or oppose this war?
Condition 3: Casualties (comparison with non-financial burden)
Suppose a foreign government attacked a key ally of the United States. In response, the United
States decides to launch a military operation to help defend the ally.
The number of US casualties would be significant.
To what extent would you support or oppose this war?
5
V. Question Wording and Perceived Cost of War
Respondents were asked about their perceived cost of the conflict as follows:
How much do you think this war would cost the United States?
1) $100 billion (not costly)
2) $300 billion (a little costly)
3) $500 billion (somewhat costly)
4) $700 billion (very costly)
5) $900 billion (extremely costly)
1. Difference in Means t-test, p-values
Baseline
Baseline
0.83
Tax
0.897
Debt
0.479
Casualties
2. Mann-Whitney U Test, p-values
Baseline
Baseline
0.741
Tax
0.919
Debt
0.352
Casualties
Tax
Debt
0.933
0.641
0.576
Tax
Debt
0.871
0.614
0.4763
6
Casualties
Casualties