When community service work is required by a school or business, there is the downside risk that people will infer that they are volunteering only because it is required and will be less likely to freely volunteer in the future. this risk is known as the?

This risk is known as the over justification effect. The over justification effect happens when there is an expected incentive such as money or a prize that decreases a person's intrinsic motivation to perform a task. In other words, the over justification effect means that those who are always rewarded or when they are rewarded have less motivation to actually get something done versus those who aren't rewarded because they hold internal values that make them wish to work hard to perform a task regardless of the reward.