BlockBeats News, September 7 — Cui Wei, Professor of Economics at University College London, recently stated at the Cheung Kong Graduate School of Business "AI × New Finance" sharing session that stablecoins are not merely payment tools, but a new form of currency that integrates the triple roles of payment, fiscal financing, and decentralized finance.

On the surface, stablecoins and the DeFi lending built on them divert bank deposits and loans, substituting for banks. However, stablecoin issuance requires U.S. short-term Treasury bonds as reserves, which directly creates demand for U.S. debt and helps alleviate the U.S. government's financing pressure and short-term debt rollover risks. Once fiscal pressure eases, the government gains room for tax cuts, thereby stimulating the real economy and potentially increasing corporate demand for bank credit.

On the optimal scale calculation, Cui Wei provided a clear magnitude assessment. He stated that the U.S. Treasury's stated goal is to push the stablecoin market to $30 trillion by 2030, equivalent to 9% of U.S. GDP. However, after model calculations by his team—taking into account bank run risks, fiscal balance, and welfare effects—the conclusion reached is that the optimal scale should be around $1 trillion, accounting for approximately 3% to 4% of GDP. Exceeding this level would significantly reduce social welfare. "To reach an extreme scale of 9%, either stablecoins would need to penetrate everyday consumer payments (such as using stablecoins to buy bottled water), or nearly all holders would need to be foreigners using them solely for cross-border settlement—both scenarios are extremely demanding."

Professor Cui Wei believes that stablecoins still have significant room for growth, but the fiscal motives behind them should be viewed rationally. He pointed out that U.S. tax revenue accounts for only 27% of GDP, far lower than Europe's 45% to 50%, which means the U.S. still has considerable fiscal potential and U.S. Treasury credit remains solid in the short term. Growth from $300 billion to $1 trillion (roughly 3 to 4 times) is feasible. However, he also cautioned that the Trump administration's push for stablecoins and its ban on central bank digital currencies is not truly about protecting privacy, but rather driven by fiscal needs—namely, financing government deficits at low cost.