The idea that citizens and voters adopt the policy preferences offered to them by the political elite meets with resistance on several grounds. Academic models of political processes tend to assume that citizens and voters have preferences, and that parties and candidates adjust their platforms to appeal to their preferences, rather than that people’s preferences are derived from the platforms offered to them by the political elite. Through introspection, people also resist the idea that their own policy preferences are formed this way (although they are more willing to accept the idea that other people adopt their expressed policy preferences this way). This chapter looks at preferences in general to discuss the way that advertising can alter preferences, the way that people are influenced by the preferences of their peers, and the way that producers can create wants that affect consumer preferences. If preferences can be altered for people’s instrumental choices, it is more likely that they can be altered for expressive choices, when what people choose does not affect what they get.