It is often said that everyone understands precisely what is meant by
the notion of probability-except those who have spent their lives
studying the matter. Upon close scrutiny, the intuitively obvious idea
of probability becomes quite elusive. Is it a subjective or objective
concept? Are random variables simply improperly measured deterministic
variables, or inherently random? What is meant by the phrase "other
things held constant" that often appears in descriptions of probability?
These questions involve fundamental philosophical and scientific issues,
and promise to elude definitive answers for some time. The same type of
difficulty arises when attempting to produce a volume on microeconomic
theory. The obvious first question-what is microeconomic theory?--