Abstract
We introduce the notion of an information structure I as being richer
than another J when for every game G, all correlated equilibrium
distributions of G induced by I are also induced by J. In particular,
if I is richer than J then I can make all agents as well off as J in
any game. We also define J to be faithfully reproducible from I when all
the players can compute from their information in I “new information”
that reproduces what they could have received from J. Our main result
is that I is richer than J if and only if J is faithfully reproducible
from I.
JEL Classification C72
Key Words
Information structure; correlated equilibrium; statistical experiment;
value of information.
