Population Pressure, Horizontal Inequality and Political Violence: A Disaggregated Study of Indonesian Provinces, 1990–2003

The study examines whether resource scarcity and inter-group inequalities drive political violence at a sub-national level in Indonesia. While population growth and horizontal inequality show little effect in isolation, their interaction significantly increases the risk of 'routine' violence. The authors find that in provinces with high population growth, greater inequality between religious groups elevates the risk of violence, suggesting that demographic pressure may amplify existing social segmentations.

• Population growth alone has a statistically significant positive effect on the risk of 'routine' violence, but it does not significantly affect 'episodic' violence.
• Land scarcity does not increase the risk of political violence in Indonesia; in some models, it is actually associated with a lower risk of episodic violence.
• Religious polarization and horizontal inequality (measured by infant mortality rates between religious groups) do not significantly increase the risk of political violence when analyzed in isolation.
• There is a strong and significant interaction effect between population growth and horizontal inequality: in provinces with high population growth, higher levels of inter-religious inequality significantly increase the risk of routine violence.
• The interaction between population growth and horizontal inequality also shows some support for increasing episodic violence, though the effect is weaker and influenced by the time period analyzed.
• Urbanization is positively associated with the risk of routine violence, which the authors note is a predominantly urban phenomenon.
• Previous experience with conflict is a very strong predictor of future violence within the same province, though violence does not appear to spread across provincial borders.
• Poorer regions (lower GDP per capita) are more likely to experience routine violence.

APA

Østby, G., Urdal, H., Tadjoeddin, M. Z., Murshed, S. M., & Strand, H. (n.d.). Population Pressure, Horizontal Inequality and Political Violence: A Disaggregated Study of Indonesian Provinces, 1990–2003. Peace Research Institute Oslo. https://cdn.cloud.prio.org/files/334bf2dd-dfed-4fe3-8828-daf2cea883dc/Population Pressure Horizontal Inequality and Political Violence.pdf?inline=true

Chicago

Østby, Gudrun, Henrik Urdal, Mohammad Zulfan Tadjoeddin, S. Mansoob Murshed, and Håvard Strand. Population Pressure, Horizontal Inequality and Political Violence: A Disaggregated Study of Indonesian Provinces, 1990–2003. Peace Research Institute Oslo, n.d. https://cdn.cloud.prio.org/files/334bf2dd-dfed-4fe3-8828-daf2cea883dc/Population Pressure Horizontal Inequality and Political Violence.pdf?inline=true.

Wikipedia

{{cite report |last1=Østby |first1=Gudrun |last2=Urdal |first2=Henrik |last3=Tadjoeddin |first3=Mohammad Zulfan |last4=Murshed |first4=S. Mansoob |last5=Strand |first5=Håvard |title=Population Pressure, Horizontal Inequality and Political Violence: A Disaggregated Study of Indonesian Provinces, 1990–2003 |publisher=Peace Research Institute Oslo |url=https://cdn.cloud.prio.org/files/334bf2dd-dfed-4fe3-8828-daf2cea883dc/Population Pressure Horizontal Inequality and Political Violence.pdf?inline=true |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{stbyndpopulation, author = {Østby, Gudrun and Urdal, Henrik and Tadjoeddin, Mohammad Zulfan and Murshed, S. Mansoob and Strand, Håvard}, title = {{Population Pressure, Horizontal Inequality and Political Violence: A Disaggregated Study of Indonesian Provinces, 1990–2003}}, institution = {Peace Research Institute Oslo}, url = {https://cdn.cloud.prio.org/files/334bf2dd-dfed-4fe3-8828-daf2cea883dc/Population Pressure Horizontal Inequality and Political Violence.pdf?inline=true}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }