A Reformulation of the Quantity Theory of Money: Globalization, Digitalization, and Exchange

This study explains why the massive expansion of the Federal Reserve’s balance sheet following the 2008-2010 crises did not generate the inflation predicted by the Quantity Theory of Money (QTM). The QTM is reformulated by incorporating three twenty-first-century structural forces: the real effective exchange rate (REER), globalization (KOF index), and digitalization (IDI). A log-log model with GLS-Newey-West corrections is estimated using U.S. quarterly data (2000 Q1-2024 Q4), and causality is tested via a VAR (3). REER and inflation are found to be bidirectionally linked, while M2 unidirectionally drives prices. A 1 percent real depreciation increases the CPI by 0.21 percentage points, whereas advances in globalization and digitalization exert persistent deflationary pressures. The expanded model (SQTM) reduces forecast RMSE by 40 percent and raises the adjusted R2 to 0.87 relative to the classical QTM and a Phillips-curve VAR. In sum, central banks should monitor REER, KOF, IDI, and money velocity, adopt flexible inflation targets, and coordinate exchange-rate policy to safeguard price stability.