<P> Information asymmetry models assume that at least one party to a transaction has relevant information, whereas the other (s) do not . Some asymmetric information models can also be used in situations where at least one party can enforce, or effectively retaliate for breaches of, certain parts of an agreement, whereas the other (s) cannot . </P> <P> In adverse selection models, the ignorant party lacks information while negotiating an agreed understanding of or contract to the transaction, whereas in moral hazard the ignorant party lacks information about performance of the agreed - upon transaction or lacks the ability to retaliate for a breach of the agreement . An example of adverse selection is when people who are high - risk are more likely to buy insurance because the insurance company cannot effectively discriminate against them, usually due to lack of information about the particular individual's risk but also sometimes by force of law or other constraints . An example of moral hazard is when people are more likely to behave recklessly after becoming insured, either because the insurer cannot observe this behavior or cannot effectively retaliate against it, for example by failing to renew the insurance . </P> <P> The classic paper on adverse selection is George Akerlof's "The Market for Lemons" from 1970, which brought informational issues to the forefront of economic theory . </P> <P> It discusses two primary solutions to this problem, signaling and screening . </P>

Informational asymmetry is a difference in efficiency. equality. relevant knowledge. signaling