During music class at the Bilkent school, third-graders sitting cross-legged on a large carpet sang "Twinkle, twinkle, little star" in Turkish, followed by "London Bridge" in English.
Ms Kocabiyikoglu, of Bilkent University in Turkey, and Ms Popescu, of INSEAD, address the problem of how to motivate managers to work harder by adjusting their pay.