San Francisco's Uber said the fee demonstrates its "continued commitment to safety" and helps fund increased costs for background checks, motor vehicle checks, driver safety education, current and future safety features in its app, and insurance. "The safety efforts themselves (background checks, ongoing safety monitoring, driver safety education, insurance, etc) are not new," spokesman Lane Kasselman said in an e-mail. Uber and other companies that engage in the practice said it helps bring out more drivers to meet increased need for their services. Arun Sundararajan, a New York University business professor who studies the sharing economy, said he thinks riders won't bristle as much when they face the new fee.