Causality (bookmark page 104) Flashcards
Correlation vs Causality (with formulae)
Examples
Drug –> Reduction of illness
More Ice-cream = More Sharks (temperature)
Associational vs Causal Concepts
Associational concept can be defined in terms of joint distribution of variables e.g., correlation, likelihood
Causal concepts cannot be defined in terms of distributions alone. e.g., spuriousness, effect, confouding. Verified through experimental control.
Define P(Y=y, do(X=x))
Probability of effect ‘y’ if treatment condition X=x were applied to the population
do-operator
Exogenous vs Endogenous variables
Exogenous variables: observed or unobserved variables that are kept unexplained in the model i.e., not modeled to be resulting from other variables in the model
Endogenous variables = effect of other exogenous/ endogenous variables
Structural Causal Model
Endogenous, Exogenous variables in the model + functions specifying how each endogenous variable is generated from other variables
Symptom := f(Disease, Other Stuff)
Disease := g(genetics, socio-economic level, etc)
Symptom/Disease = Endo
Other Stuff could be modeled to be exo
First Order Markov Assumption
New state depends on previous state and states prior to that need not be considered
Blocked paths
Chain:
A –> B –> C
blocked path: C conditioned on B is independent of A
Fork:
A –> B
A –> C
Blocked path: B conditioned on A is independent of C
Unblocked path: B (not conditioned on A) is associated with C due to common cause A
Bookmark
https://www.youtube.com/watch?v=U1S8Rq8IcrY&list=PLoazKTcS0Rzb6bb9L508cyJ1z-U9iWkA0&index=32