Final answer:
A purposive incentive is the opportunity to contribute to a worthy goal or purpose. An example is membership in the ACLU increasing after the 9/11 attacks.
Step-by-step explanation:
A purposive incentive is defined as the opportunity to contribute to a worthy goal or purpose. It is when someone joins and contributes money to a group because they want to help the group achieve its goals. For example, membership in the American Civil Liberties Union (ACLU) increased after the 9/11 attacks because people were concerned about the government's antiterrorism campaign harming civil liberties.