In a theory of language policy, managers are individuals or institutions with authority to require others to change their language practices or beliefs. Advocates are individuals or institutions who want the same result, but lacking any power to enforce, can only try to persuade. Language academies can be managers or advocates. Standardization is often the work of individual language reformers and missionaries, including those who develop writing systems. Advocates can persuade governments to implement language policy: examples are Hebrew, Irish and Maori. Examples of strong language managers are powerful leaders like Atatürk, Lenin, Stalin, and Lee Kuan Yew. But even powerful leaders find it hard to deal with the existence of policies at other levels and to implement unpopular policies.