Decades of evidence from individual-choice experiments have documented that subjects do not always satisfy the assumptions of consumer theory and of expected utility theory. Some departures from the standard model can be accommodated while maintaining the assumption that people do have stable preferences. Experiments on anchoring effects are more troubling as they suggest that many people do not have fixed or slowly changing preferences. A defender of the standard models might argue that this is not relevant to most everyday consumer decisions, and that an average person with enough experience will have relatively fixed preferences for common market goods. This suggests that experience with the goods and decisions in question may be important in the stability of preferences. Since people are relatively familiar with risky monetary choices, this in turn suggests that decisions about uncertain prospects (lotteries) might be relatively stable.If the monetary valuation of goods and gambles is based on constant underlying preferences, choices should be independent of irrelevant prior "anchoring" questions. In the case of lotteries, Johnson and Schkade (1989) showed that asking subjects whether they would prefer a fixed amount (the anchor) to a given gamble affected subsequently stated certainty equivalents. Chapman and Johnson (1999) had subjects generate a random anchor from their Social Security Number (SSN