See statement by the Royal Swedish Academy of Sciences.
“Contract theory has greatly influenced many fields, ranging from corporate governance to constitutional law. Thanks to the work of Oliver Hart and Bengt Holmström, we now have the tools to analyse not only contracts’ financial terms, but also the contractual allocation of control rights, property rights, and decision rights between parties. The contributions by the laureates have helped us understand many of the contracts we observe in real life. They have also given us new ways of thinking about how contracts should be designed, both in private markets and in the realm of public policy.”
See also video of announcement.