Development of a Python-Based Fiscal Projection Model to Support Indonesia's Development Planning for 2045

Abstract

This study develops an integrated Python-based fiscal projection model to evaluate the sustainability of Indonesia's fiscal policy in achieving long-term development targets towards Indonesia 2045. Specifically, this study has three main objectives: (1) to develop an integrated Python-based fiscal projection model that combines historical data and 2045 development targets, (2) analyze three fiscal policy scenarios through a deterministic simulation approach to assess Indonesia's ability to achieve development goals, and (3) formulate policy recommendations based on simulation results to maintain long-term fiscal sustainability in accordance with fiscal management training data results. The model was built using official historical fiscal data from the Central Statistics Agency (2019–2024), which was then engineered into key fiscal ratios before being used in the simulation process. Three policy scenarios, Fiscal Constrained, Balanced Reform, and Transformational, were evaluated to assess the interaction between economic growth, fiscal capacity, and development indicators. The results of the study show a significant trade-off between accelerating economic growth and long-term fiscal stability. Although the Transformational scenario is capable of increasing GDP per capita to exceed the threshold of a developed country, none of the scenarios meet the safe deficit limit, meaning that developed country status cannot be achieved by 2045. These findings confirm that success in achieving Indonesia 2045 requires an integrated policy approach that combines tax base expansion, spending efficiency, and strategic investment in human development.