The number of teachers employed depends on State and local expenditures for education. Earnings for special education teachers are comparable. Earnings in private schools generally are lower. Many public school teachers belong to unions, such as the American Federation of Teachers and the National Education Association, that bargain with school systems over wages, hours, and the terms and conditions of employment. In some schools, teachers receive extra pay for coaching sports and working with students in extracurricular activities.
Some teachers earn extra income during the summer working in the school system or in other jobs.