The causal-inference tag has no wiki summary.
34
votes
14answers
6k views
Under what conditions does correlation imply causation?
We all know the mantra "correlation does not imply causation" which is drummed into all first year statistics students. There are some nice examples here to illustrate the idea.
But sometimes ...
5
votes
3answers
2k views
X and Y are not correlated, but X is significant predictor of Y in multiple regression. What does it mean?
X and Y are not correlated (-.01); however, when I place X in a multiple regression predicting Y, alongside three (A,B, C) other (related) variables, X and two other variables (A,B) are significant ...
18
votes
3answers
1k views
Statistics and causal inference?
In his 1984 paper "Statistics and Causal Inference", Paul Holland raised one of the most fundamental questions in statistics:
What can a statistical model say about
causation?
This led to his ...
37
votes
5answers
2k views
Does causation imply correlation?
Correlation does not imply causation, as there could be many explanations for the correlation. But does causation imply correlation? Intuitively, I would think that the presence of causation means ...
12
votes
4answers
2k views
How are propensity scores different from adding covariates in a regression, and when are they preferred to the latter?
I admit I'm relatively new to propensity scores and causal analysis.
One thing that's not obvious to me as a newcomer is how the "balancing" using propensity scores is mathematically different from ...
13
votes
4answers
1k views
From a statistical perspective, can one infer causality using propensity scores with an observational study?
Question: From the standpoint of statistician (or a practitioner), can one infer causality using propensity scores with an observational study (not an experiment)?
Please, do not want to start a ...
3
votes
2answers
107 views
What test should I use to determine if a policy change had a statistically significant impact on website registrations?
A client's website was operating under a certain policy for membership sign ups for over a year. At the start of October 2012 the client implemented a new policy for sign ups that was supposed to ...
8
votes
3answers
381 views
Random assignment: why bother?
Random assignment is valuable because it ensures independence of treatment from potential outcomes. That is how it leads to unbiased estimates of the average treatment effect. But other assignment ...
13
votes
2answers
723 views
What's the relation between hierarchical models, neural networks, graphical models, bayesian networks?
They all seem to represent random variables by the nodes and (in)dependence via the (possibly directed) edges. I'm esp interested in a bayesian's point-of-view.
8
votes
2answers
1k views
Are mediation analyses inherently causal?
I am interested in testing a simple mediation model with one IV, one DV, and one mediator. The indirect effect is significant as tested by the Preacher and Hayes SPSS macro, which suggests the ...
3
votes
2answers
656 views
How to test whether correlation measures differ when controlling or not for a third variable?
If the correlation between demographic dissimilarity and satisfaction is $r=.-14$ and the partial correlation, with career development partialled out, between demographic dissimilarity and ...
4
votes
3answers
205 views
Formal definition of random assignment
I am looking for a formal definition of random assignment.
Let $\mathbf{Z}$ be a vector of treatment assignments in which each element is 0 (unit not assigned to treatment) or 1 (unit assigned to ...
1
vote
2answers
101 views
Must there be “an effect to be mediated” in mediational analysis (i.e., must IVs & DVs be correlated)?
Baron and Kenny outlined several steps to aid in determining if a mediational analysis is appropriate to test a particular hypothesis. The very first step was "Show that the initial [independent] ...
