Economic incentives and social preferences can impact public policies. When policies focus only on self-interest, they may reduce altruism and ethical behavior, making them less effective. Research from 51 studies shows that this effect is common, but positive impacts can also occur. A model was created to show how self-interest and social preferences can either work together or against each other. This means that incentives can change people's behavior in unexpected ways, similar to the Lucas Critique in economics.