Public choice theory is an economic theory that applies the principles of economics to political decision-making. It suggests that individuals in the political sphere, such as politicians, bureaucrats, and voters, act in their own self-interest, similar to how they would in the marketplace. This perspective helps explain why government decisions may not always align with the public good. The theory highlights issues like government failure and rent-seeking, where individuals or groups seek to gain benefits through political means rather than through productive economic activities. By understanding these dynamics, public choice theory aims to improve the efficiency and effectiveness of government policies.