<![CDATA[Non-oil and gas income tax (PPh nonmigas) accounts for the largest share of Indonesia's tax revenue, making it a critical pillar of state fiscal capacity. However, its performance is empirically vulnerable to macroeconomic shocks, yet most prior studies employed static regression methods incapable of distinguishing short-run from long-run dynamics. This study aims to analyze the effect of economic growth (GRWTH), inflation (INF), real effective exchange rate (REER), and real effective annual rate (EAR) on Indonesia's real PPh nonmigas revenue using annual time-series data for 1984–2025. The Autoregressive Distributed Lag–Error Correction Model (ARDL-ECM) is employed to simultaneously identify short-run and long-run relationships, supported by causality validation through VAR Toda-Yamamoto. The bounds test confirms cointegration with an F-statistic of 19.2495, exceeding the 1% critical value. In the long run, economic growth exerts a significant positive effect (coefficient 11.3951), inflation a significant negative effect (coefficient ?8.4082), and REER a significant negative effect (coefficient ?3.2950), while EAR remains insignificant. In the short run, only the first lag of inflation is significantly positive, reflecting the Olivera-Tanzi mechanism. The ECT coefficient of ?0.2175 indicates a 21.75% annual adjustment toward equilibrium. The Toda-Yamamoto test confirms the absence of reverse causality, validating estimates as free from simultaneity bias. These findings affirm that policies promoting quality growth, maintaining low and stable inflation, and managing a competitive REER constitute the three main pillars in ensuring the sustainability of Indonesia's real non-oil and gas income tax revenue.]]>
