Answer: His Ex-wife

Robert Lucas is a highly accomplished American economist well known for his investigations into rational expectations, theory of supply, and behavioral economics. In 1995, he won the Nobel Memorial Prize in Economic Sciences but only received his award and half the cash prize.

Where did the other half go? To his ex-wife Rita Lucas, who put a clause in their 1988 divorce that, should Robert win the Nobel Prize within 7 years of their divorce, she would receive half the money. She might not have thought highly of his qualifications as a husband, but she clearly stood with the rest of the world in regarding him as one of the most brilliant economists alive.