Book excerpt: Indonesia's diverse economic landscape and growing importance in the global and regional stages warrant deeper understanding of the economy at sub-national levels. This book by the Asia Competitiveness Institute (ACI) is an update of ACI's annual study of the competitiveness landscape of 34 Indonesian provinces. With 100 indicators covering four environments and 12 sub-environments of competitiveness, the study's unique methodology incorporates comparative strengths and weaknesses, and 'what-if' policy simulations aimed at policy suggestions for each province. This fourth instalment continues to feature a structure and graphical presentation that offer investors an overview of each province's competitiveness landscape. Coupled with evidence-based findings and analyses, this book is a recommended read for policymakers, stakeholders and general audience interested in the economic developments of Indonesia's provinces.