We study an impatient, risk-neutral government that cannot commit to a particular debt path, financed by competitive lenders. In equilibrium, debt adjusts slowly toward a debt-to-income target, exacerbating booms and busts. Strikingly, gains from trade dissipate when trading is continuous, leaving the government no better off than in financial autarky, owing to a sovereign “debt ratchet effect.” Moreover, citizens who are more patient than their government are strictly harmed. We characterize equilibrium debt dynamics, ergodics, and comparative statics when income follows a geometric Brownian motion and analyze devices that allow the sovereign to recapture gains from trade.

Open banking facilitates data sharing consented to by customers who generate the data, with the regulatory goal of promoting competition between traditional banks and challenger fintech entrants. We study lending market competition when sharing banks’ customer transaction data enables better borrower screening for fintechs. Open banking promotes competition if it helps level the playing field for all lenders in screening borrowers; however, if it over-empowers fintechs, it can also hinder competition and leave all borrowers worse off. Due to the credit quality inference from borrowers’ sign-up decisions, this remains true even if borrowers have the control of whether to share their banking data. We also study extensions with fintech affinities and data sharing on borrower preferences.

We provide causal evidence on the value of asset pledgeability by exploiting a unique feature of Chinese corporate bond markets: bonds with identical fundamentals are traded on two segmented markets with different rules for repo transactions. Using a policy shock that rendered AA+ and AA bonds ineligible for repo on one market only, we compare how bond prices changed across markets and rating classes around this event. When the haircut increases from 0% to 100%, bond yields increase by 39 bps to 85 bps. These estimates help us infer the magnitude of the shadow cost of capital in China.