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1 vote
0 answers
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Undirected graphs and implications of independence (Wasserman chapter 18)

In Wasserman's All of Statistics chapter 18, he defines the following undirected graph: Let $V$ be a set of random variables with distribution $\mathbb{P}$. Construct a graph with one vertex for each ...
NovicePatience's user avatar
1 vote
1 answer
148 views

Conditional independence situation with three variables

Say we have three random variables, $X, Y$ and $Z$, where $X$ is independent of $Z$ (but not $Y$). Does $E\bigg[ \dfrac{X}{f(Y,Z)} \bigg| Y \bigg] = E[X|Y] * E\bigg[ \dfrac{1}{f(Y,Z)} \bigg|Y \bigg]$? ...
bob's user avatar
  • 725
2 votes
1 answer
1k views

Does mutual independence of X, Y, Z implies conditional independence of X and Y, given Z

Given mutual independence of 3 r.v.s X, Y, Z, can we conclude that X and Y are independent, given Z? Note that I am interested in case when all 3 r.v.s are mutually independent, not only pair X, Y. In ...
Eugene Loy's user avatar
4 votes
1 answer
490 views

Given random variables $X,Y,Z$, under what conditions is $P(Y|X)=P(Y|X,Z)$?

From this link, where the statement is given for events and not random variables, I gather that for random variables $X,Y,Z$, $P(Y|X)=P(Y|X,Z)$ only if $P(Y,Z|X)=P(Y|X)P(Z|X)$? Does this imply that $Y$...
Yandle's user avatar
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