1. Intervening relationships: X1  X2  Y

2. News from science – what?
Probability of Alzheimer’s
Severity of Rheumatoid Arthritis

3. Nonsensical correlation
What could explain this?
Rheumatoid Arthritis
Alzheimer’s

4. An illustration with a causal model
There is a variable (Z) that intervenes between A and B if: A Z B

5. A test of whether Z intervenes between A and B
Look at the relationship between A and B, controlling for Z
This means, that for all values of Z, you should look at the relationship between A and B.

6. Scatterplot illustration of when there is an intervening relationship
All people
Alzheimer’s
Only high levels of ibuprofen
Only small levels of ibuprofen
Alzheimer’s
Rheumatoid
Arthritis
Alzheimer’s
Rheumatoid
Arthritis
Rheumatoid
Arthritis

7. There is a variable that intervenes between A and B if:
Rheumatoid arthritis
Ibuprofen
Alzheimer’s
NOT
Ibuprofen
Rheumatoid arthritis
Alzheimer’s

8. News from science – fluoride causes cancer?
Water Fluoridation
Cancer rates (cities around world)

9. Strong correlation: causation?
What could be the reason cancer rates are higher?
Fluoride
Cancer rates

10. Scatterplot illustration
All cities
Fluoridation
Only poor cities
Only rich cities
Fluoridation
Cancer rates
Fluoridation
Cancer rates
Cancer rates

11. What is it?
Fluoridation
Wealth
Cancer
Wealth
Fluoridation
Cancer

12. So, what the heck? Intervening and spurious are the same empirically?
So, how do we know the difference?

13. Spurious and intervening relationships are Observationally equivalent
Theory
Spurious and intervening relationships are
Observationally equivalent

14. Here are some examples that are not observationally equivalent
Perhaps there are simply alternative causes of something…
Or is it intervening?

15. Does being white cause education which causes income?
Race (being white)
Education
Income
Income
Race (being white)
Education

16. Is this an intervening relationship
Is this an intervening relationship? Being white causes education, which then causes income
White
Non-white
High income 70 25
Low income 30 75

17. What are the arguments?

18. Is this an intervening relationship
Is this an intervening relationship? Being white causes education, which then causes income
Only those with high education
White
Non-white
High income 90 60
Low income 10 40

19. Is education intervening?
Only those with low education
White
Non-white
High income 40 10
Low income 60 90

20. Conditional effects

21. Education causes political tolerance?
Not in the former Soviet Union:
Political tolerance
Education

22. Does perceived political advantage reduce the likelihood of litigation?
(in the case of the Moscow Theater case)

23. What causes people to litigate against their government
What causes people to litigate against their government? (with regard to the Moscow Theater incident)
How should this variable be measured?

24. Measure of litigation (with regard to the Moscow Theater incident)
Are you one of the plaintiffs in this lawsuit?
freq vars = litigant.

25. Theory from the U.S.: Political Disadvantage
When people feel alienated from traditional avenues of participation or representation, then they may be more likely to participate in litigation.

26. Political Disadvantage
Measure: the highest answer from the following two questions
How well do you believe that President Putin represents your interests?
How well do you believe that the current Duma represents your interests?
very well, rather well, not very well, not at all well

27. Crosstab Analysis: Is political advantage related to litigation?

28. Theory People tend to use procedures that they believe will be fair
Thus, perception of fairness of the courts causes litigation
How carefully will the court listen to the hostages side of the story? Very carefully, rather carefully, somewhat carefully, not at all carefully

30. Theory
Why is it that when people think the courts are more unfair, they are MORE likely to litigate?
UGH! And: what? what is the reason?

31. Anger
Could it be that the more angry people are, they more likely they want to engage in an expressive activity –
In other words, litigation is not about the fairness of courts – it is about expressing how angry you are
How to test that?

32. Perhaps the negative correlation between perceptions of fairness and litigation is particularly negative when people have reason to be angry – they are politically disadvantaged

33. In this case, we are testing a conditional relationship:
The effect of one independent variable is intensified OR mitigated, depending on the values of another variable
The negative effect of procedural justice will intensify as political advantage decreases

34. Perceived probability
of judicial fairness
Anger (political disadvantage)
Litigation
Proc Just
Proc Just
Proc Just
Low anger
High PD
High anger
High PD
Med anger
Med PD

36. A more political example…
So, let’s look at the relationship between political interest and participation

37. Political interest
Self efficacy
Participation

38. Political interest and political participation
| How much interest do you have in political
polpartbes | affairs
c | No intere Not very A fair am A great d | Total
0 | |
| |
1 | |
| |
2 | |
| |
Total | | 1,062
| |
Kendall's tau-b = ASE = 0.026

39. In other words, how do we find out that it is the ONLY reason?
Intervening relationship A causes B which causes C.
A causes C because it causes B which then causes C.
So, now what do we need to do to see if political interest has an effect on participation BECAUSE it causes self efficacy?
In other words, how do we find out that it is the ONLY reason?

40. Political interest and participation when self efficacy is high
| How much interest do you have in political
polpartbes | affairs
c | No intere Not very A fair am A great d | Total
0 | |
| |
1 | |
| |
2 | |
| |
Total | |
| |
Kendall's tau-b = ASE = 0.031

41. Political interest and participation when self efficacy is low
| How much interest do you have in political
polpartbes | affairs
c | No intere Not very A fair am A great d | Total
0 | |
| |
1 | |
| |
2 | |
| |
Total | |
| |
Kendall's tau-b = ASE = 0.046

42. So, does controlling for political interest mitigate the effect of self efficacy?

43. Self efficacy and participation when political interest is medium
| Compared to most political leaders, how much better or
polpartbes | worse could you personall
c | Much wors Somewhat Equally Somewhat Much bett | Total
0 | |
| |
1 | |
| |
2 | |
| |
Total | |
| |
Kendall's tau-b = ASE = 0.040

44. Self efficacy and participation when political interest is high
| Compared to most political leaders, how much better or
polpartbes | worse could you personall
c | Much wors Somewhat Equally Somewhat Much bett | Total
0 | |
| |
1 | |
| |
2 | |
| |
Total | |
| |
Kendall's tau-b = ASE = 0.053