Information Rent

Definition

An information rent is the surplus or economic rent that a privately informed agent must be paid (beyond their reservation utility or the principal's first-best offer) because the agent could profit by lying about their private information. It arises directly from asymmetric information: if the principal knew the agent's true type or effort, they could force the agent down to their reservation level. But under asymmetry, the principal must pay the agent enough to make truthful behavior preferable to deception. Information rents are not payment for effort or value created; they are pure deadweight loss from the principal's perspective—costs imposed by informational asymmetry that could not arise under complete information.

In the Book

Chapter 2 (section 2.4) introduces information rents as the central distributional consequence of asymmetric information. Under complete information, the principal with all bargaining power can reduce each agent type to zero utility. Under adverse selection, if the principal offers the first-best menu to an agent who knows their true type, the efficient agent will mimic the inefficient one's contract if it pays more. To prevent this, the principal must offer the efficient agent strictly positive utility—the agent earns a rent simply by having private knowledge of their efficiency.

The book shows formally that even when the inefficient agent gets zero utility (the hardest participation constraint to satisfy), the efficient agent must receive a positive information rent equal to Δc q̄, where Δc is the efficiency gap and q̄ is the inefficient agent's output. Reducing the inefficient agent's output reduces this rent. The principal's optimization problem involves choosing how much to "give up" in information rents to reduce distortions.

The rent appears in multiple forms across the book. In moral hazard (Ch. 4), the agent earns a rent from their private knowledge of their effort level. In dynamic settings (Ch. 8), information rents can grow over time as the principal learns and updates beliefs. The book also shows that when both principal and agent are risk-averse, the distribution of information rents between them affects efficiency—a risk-averse principal may be willing to pay the agent more rent to transfer risk to the risk-neutral agent.

Why It Matters

Information rents reveal a pure cost of asymmetric information to society. Unlike the distortions in quantity or effort (which might be offset by other gains), information rents represent pure surplus transfers with no productive purpose. They quantify exactly how much the informed party profits from their information advantage. Understanding rent distribution is central to inequality analysis, regulation design, and institutional architecture: it shows why principals want to acquire information, why agents protect information, and how much resources societies devote to learning others' private information.