A common market has no barriers to trade among member countries, includes a common external trade policy, and allows factors of production to move freely among members.
A monetary union has all the features of a common market and participating countries have a common currency.
Asymmetric information is an instance of market failure.
It is when one party to a transaction possesses greater information or knowledge than the other party. e.g. when a seller possesses greater information than the buyer or when a buyer possesses greater information than the seller.
Individuals know when they have a more healthy lifestyle while their insurers might not be privy to such information due to privacy laws
