Peiyi Jin

Welcome to my website!

I'm a Ph.D. candidate in the Department of Economics at National University of Singapore (NUS), currently on the 2025/26 academic job market. I'm supervised by Prof. Sumit Agarwal.

Research Interests: Fintech, Digital Economy, and Household Finance.

Job Market Paper

Abstract:
This paper studies how digital technologies alter household responsiveness to income shocks by increasing the salience of consumption. I evaluate a government-led intervention in Singapore that provides real-time energy usage feedback through a mobile app. Using proprietary banking transaction data and a staggered rollout design, I find that treated households reduce utility payments by approximately $21 per month. This reduction is not driven by price changes or liquidity constraints but by increased cognitive attention to consumption. The intervention also produces behavioral spillovers: households reduce spending on paper goods, carbon-intensive foods, and taxi rides. Untreated residents living near treated areas exhibit similar changes, suggesting that salience effects diffuse spatially. These findings challenge the Permanent Income Hypothesis by showing that visibility increases short-run consumption elasticity. The results have implications for monetary and fiscal policy design. Digital salience can raise marginal propensities to consume, especially among liquidity-constrained households, and may strengthen policy transmission in heterogeneous-agent macroeconomic models.

Working Papers

I. Blockchain

Abstract:
This paper investigates how tax-planning strategies affect market liquidity and credit risks in Decentralized Finance (DeFi) lending. Using an exogenous tax shock on cryptocurrency gains and millions of transactions, we show that tax-motivated borrowing to defer capital gains taxes significantly reduces liquidity—particularly among stablecoin borrowers, high loan-to-value borrowers, and those holding assets long-term. Instrumental variable estimates indicate that tax-induced illiquidity more than doubles defaulted loan values. Robustness checks confirm these effects among highly tax-sensitive borrowers. The findings highlight implications for market stability, tax revenue forecasts, and the regulation of digital asset taxation.

Abstract:
This paper investigates whether cryptocurrencies have become a new conduit for laundering diverted foreign aid. Using World Bank aid disbursement data from 2018 to 2024, linked with forensically tagged on-chain Bitcoin transactions and off-chain exchange activity, we document systematic surges in crypto transactions for anonymous wallets after disbursements, especially on exchanges located in tax-haven jurisdictions. A one-standard-deviation increase in lagged aid is associated with a 0.51 log-point rise in anonymous transactions on tax-haven exchanges—approximately a 66% increase—concentrated in newly created wallets and fading within two quarters. Network analysis reveals a real-time laundering pattern: funds flow through regulated platforms, then through mixers and tax-haven exchanges, mirroring the classic placement, layering, and integration stages. Off-chain data confirm spikes in transactions on suspect, lightly regulated platforms. To address endogeneity in aid allocation, we use an IV strategy based on historical aid shares interacted with governance quality. Overall, our findings suggest that cryptocurrencies are increasingly used for offshore banking in concealing aid diversion. Our study shows how blockchain forensics can trace hidden financial flows and offers new tools for anti-corruption and crypto regulation.

II. Fintech Lending

Abstract:
This paper examines the impact of credit data sharing among competitive banks of different sizes in open banking. Analyzing data from three predecessors of Bank of America, we find that information sharing enhances predictive capabilities and increases market lending profit as the network expands. Banks that share loans spanning a wider range of collateral drive most of the predictive gains. However, competition creates unequal benefits, with smaller banks gaining while the largest bank loses borrowers and profits. These results underline the importance of effective bargaining for cooperative sharing. We also explore the Nash equilibrium for optimal outcomes in a competitive lending market.