The Amazon.com book description for The Secret of TSL says:
"William G. Ouchi studied 442 schools in Boston, Chicago, Houston, New York City, Oakland, St. Paul, San Francisco, and Seattle that have embraced school decentralization. He shows how decentralization has improved school performance as measured by standardized tests. Explaining the key to school success, Ouchi asserts that principals must be given control of their budgets and other authority. When they are empowered, they allocate funds to increase the number of teachers and lower the Total Student Load (TSL) per teacher. TSL is the key factor in school performance. Principals with autonomy invariably lower their school's TSL."