유튜브 프리미엄 지수를 활용한 디지털 재화의 구매력 평가설(PPP) 실증 연구

The accelerating digital transformation of the global economy has raised the need to reassess the validity of traditional Purchasing Power Parity (PPP) indicators. The widely used informal PPP metric, the Big Mac Index (BMI), suffers from structural limitations, as its prices are distorted by non-tradable factors such as local labor and rental expenses. Focusing on digital goods that are free from such physical constraints, this study proposes the “YouTube Premium Index (YPI),” a new informal PPP indicator based on the globally standardized price of YouTube Premium, and evaluates its validity using data from 40 countries. The empirical results show that the Law of One Price does not hold even in the digital goods market; cross-country price differences reach approximately 12.8-fold, far exceeding the 3.1-fold disparity observed in Big Mac prices within the same sample. Regression analysis identifies GDP per capita as the only statistically significant determinant of price differences, while population size, internet penetration, and digital content payment rates show no meaningful effects. Crucially, the comparison of explanatory power (R2) reveals that GDP per capita accounts for only 46.5% of BMI variation but explains a robust 76.8% of YPI variation. This high explanatory power suggests that the price is primarily determined by national purchasing power, reflecting a highly calculated Third-Degree Price Discrimination strategy rather than a natural long-term PPP equilibrium. Overall, the study highlights the potential of YPI as a cleaner tool for PPP assessment in the digital economy and presents new implications for understanding how monopolistic market structures leverage national income levels to optimize pricing.