The Computer Science Colloquium

Rohit Parikh
(Computer Science, Mathematics, Philosophy
Brooklyn College and CUNY Graduate Center)

"Some Puzzles about Probability"

Probability theory, which is a basis for decision theory has always been plagued by paradoxes, ever since the St. Petersburg paradox of the 18th century. There have been many interesting paradoxes since then.

Some are paradoxes only because people seem to act in an "irrational" way. Some are paradoxes because the problem makes unrealistic mathematical assumptions. And some actually do appear to be paradoxes.

Thus, can I know something about the color of my hat merely by seeing the hats that others are wearing, even when all colors are chosen randomly and independently?

Can two people both get richer by exchanging envelopes that they are holding?

Can a drug be good for men and good for women but bad for adults?

We will discuss these questions, as well as prove a surprising new result about probabilistic conditionals.

The Colloquium is supported by generous contributions from the Bloomberg, Information Builders, Inc., and Netlogic, Inc.