Publication Type
PhD Dissertation
Version
publishedVersion
Publication Date
12-2025
Abstract
This dissertation examines how policy design shapes household behavior, platform incentives, and welfare in fiscal and digital monetary environments. It combines theoretical modeling, quantitative analysis, and insights from the expanding literature on digital payments and fiscal expectations.
Chapter 1 studies household responses to anticipated consumption-tax changes in a heterogeneous-agent model with both new and second-hand durable goods. The model replicates the empirically observed spike-and-reversal in durable-goods spending around tax reforms and shows that intertemporal stockpiling is especially pronounced in secondary markets. Transitional households bear the largest welfare losses when future tax increases are preannounced, whereas high-type households benefit less due to smoother consumption paths. Counterfactual exercises indicate that stepwise tax increases generate smoother adjustment dynamics; temporary tax cuts deliver limited stimulus under adverse shocks; and postponed tax changes can generate short-run welfare losses as households revise saving and purchase timing.
Chapter 2 develops a monetary model in which a private platform issues a digital currency and uses payment data to improve matching for online sellers. The economy features online sellers who benefit from data-driven customization and offline sellers who accept multiple payment methods without comparable data advantages. Privacy costs interact with participation decisions to generate feedback effects and multiple equilibria, including one with widespread digital adoption and another with adoption collapse. Alternative privacy-cost specifications shape welfare, platform power, and the equilibrium share of online sellers, and they change the effectiveness of subsidies under both first-best and second-best allocations. The analysis shows that data-sharing mandates can reduce platform market power and raise consumer welfare, while privacy regulation must trade off protection against the efficiency gains from personalized matching—providing guidance for ongoing debates on payment-platform regulation, competition policy, and user data rights.
Chapter 3 synthesizes key mechanisms from the literature on digital currency, privacy, platform power, and fiscal expectations. It highlights how personalized pricing, data exclusivity, asymmetric privacy, and managed anonymity interact in modern payment systems and discusses their implications for policy design and welfare.
Degree Awarded
PhD in Economics
Discipline
Macroeconomics
Supervisor(s)
JACQUET, Nicolas Laurent
First Page
1
Last Page
163
Publisher
Singapore Management University
City or Country
Singapore
Citation
QIU, Feng.
Essays on macroeconomics of fiscal and monetary policies. (2025). 1-163.
Available at: https://ink.library.smu.edu.sg/etd_coll/821
Copyright Owner and License
Author
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.