We show that the price of a Treasury bond and an inflation‐swapped Treasury Inflation‐Protected Securities (TIPS) issue exactly replicating the cash flows of the Treasury bond can differ by more than $20 per $100 notional. Treasury bonds are almost always overvalued relative to TIPS. Total TIPS‐Treasury mispricing has exceeded $56 billion, representing nearly 8% of the total amount of TIPS outstanding. We find direct evidence that the mispricing narrows as additional capital flows into the markets. This provides strong support for the slow‐moving‐capital explanation of arbitrage persistence.

What determines securitization levels, and should they be regulated? To address these questions we develop a model where originators can exert unobservable effort to increase expected asset quality, subsequently having private information regarding quality when selling ABS to rational investors. Absent regulation, originators may signal positive information via junior retentions or commonly adopt low retentions if funding value and price informativeness are high. Effort incentives are below first‐best absent regulation. Optimal regulation promoting originator effort entails a menu of junior retentions or one junior retention with size decreasing in price informativeness. Zero retentions and opacity are optimal among regulations inducing zero effort.