Because China is the world's fastest growing economy, the Chinese school system has a huge demand for English teachers at all levels. Teaching English as a second language (ESL) offers a plethora of benefits, such as developing a more critical approach to cultural understanding, more opportunities for travel, overseas experience during a time of global fever, potential to save money, and improved communication skills. For most schools, the only prerequisites are being a native English speaker with a college degree, even if that degree isn't in teaching. Teachers can usually choose between a one-year or half-year contract. Pay varies depending on the school and location. The biggest cultural challenge may be found in the classroom when trying to encourage student participation. Teachers have to invest a lot of creative energy in establishing an engaging learning environment.