Working Papers
WP9 - Butter, Guns, and Ice Cream under Climate Shocks: Scarcity Pricing, Predation, and Price Stabilization
Anna Balestra, Department of Economic Policy, Università Cattolica del Sacro Cuore & International Peace Science Center (IPSC)
Raul Caruso, Department of Economic Policy, Università Cattolica del Sacro Cuore & International Peace Science Center (IPSC) & CESPIC, Catholic University “Our Lady of Good Counsel”
Abstract
This preliminary note aims to provide a theoretical model to accommodate the apparent contradictions emerging in the literature on the climate change–violent conflict nexus. In particular it builds on the butter–guns–ice-cream framework of Caruso (2010) to study how climate shocks can influence the emergence of violence between groups when agriculture is the main economic activity. Two groups allocate a fixed endowment between contested agricultural production (“butter”) and coercion (“guns”). The safe activity (“ice cream”) yields diminishing marginal returns and is determined residually by the budget constraint once butter and guns are chosen. A common climate shock shifts agricultural productivity. Allowing exposure to differ across groups generates realized asymmetries in the contested production. In a further extension, the relative price of the contested good responds endogenously to effective scarcity. In fact, the model nests two mechanisms within a unified structure. The first is an opportunity-cost margin, operating through the returns to peaceful activity. The second is a rapacity (prize-value) margin, operating through the value of contested production. We allow conflict to be inconclusive by modeling stalemate in the contest success function. In addition, we introduce endogenous destructiveness, decreasing in aggregate coercion. We also incorporate an institutional-capacity parameter that moderates violence by dampening scarcity-driven price spikes. The analysis proceeds from a benchmark to a sequence of extensions. The benchmark delivers a tractable equilibrium characterization and transparent sufficient conditions for the main comparative statics. The extensions show how endogenous destruction, scarcity pricing, and price stabilization attenuate incentives and generate empirically relevant nonlinearities, without overturning the core sign predictions.
__________________
WP8 - Climatic Shocks and Conflicts Across Agricultural Livelihoods and Agrarian Contexts: Evidence from West Africa
Giordana Sabella, Department of Economics and Management, University of Florence
Tulia Gattone, Department of Economics and Management, University of Florence
Donato Romano, Department of Economics and Management, University of Florence
Luca Tiberti, Department of Economics and Management, University of Florence & Partnership for Economic Policy (PEP)
Abstract
This paper examines how climatic shocks affect conflict risk across heterogeneous livelihood systems in four rain-fed, agriculture-dependent West African economies — Burkina Faso, Niger, Nigeria, and Côte d’Ivoire — over 2010–2023. Combining geocoded household panel data with high-resolution climate anomalies and conflict events, we estimate the effect of growing-season droughts and excess rainfall on post-harvest conflict incidence. Results show strong spatial and livelihood heterogeneity driven by the interaction between household and local livelihood structures: droughts increase conflict risk in mixed-livelihood areas in Burkina Faso and Côte d’Ivoire, in pastoral-dominated areas in Nigeria irrespective of household type, and in farm-dominated systems in Niger, while wet anomalies display more context-dependent effects, reducing conflict under moderate conditions but increasing tensions under extreme rainfall in mixed and flood-prone areas. We document transmission channels consistent with the opportunity cost mechanism — through lower agricultural productivity, reduced farm revenues, and labor reallocation away from off-farm activities — showing that climate-induced income shocks erode livelihood viability. By linking micro-level climatic stress to localized conflict outcomes, the paper highlights the moderating role of agrarian structure in shaping vulnerability to climate change and underscores the need for adaptation and social-protection policies tailored to specific livelihood systems.
__________________
WP7 - Drought, Kinship, and Conflict in West Africa
Chiara Livorno, Department of Economics and Management, University of Florence
Luca Tiberti, Department of Economics and Management, University of Florence & Partnership for Economic Policy (PEP)
Abstract
Weather shocks are frequently associated with heightened violence in agro-pastoral regions, yet the social processes linking weather-induced livelihood pressure to conflict remain insufficiently understood. This study examines whether spatial configurations of community lineages are associated with variation in community-level conflict responses to localized drought shocks. Across West Africa (1997–2022), we combine spatial panel data on drought exposure, conflict events, and the ancestral geography of lineage ties. We find that, conditional on ancestrally connected locations remaining climatically unaffected, drought exposure is associated with a 20-percentage-point lower predicted conflict incidence in clusters embedded in extended lineage networks relative to otherwise comparable clusters with more localized lineage structures. These patterns are consistent with a mechanism whereby social and institutional linkages formed across space condition access to nonlocal support and mobility-based adaptive capacity when climatic conditions deteriorate locally but not covariately. Complementary household panel data from Mali (2018–2021) show that households linked to spatially extended lineage networks experience smaller contractions in annual food expenditures and family remittance inflows following drought shocks. Overall, the findings highlight how historically constituted institutions connecting households across space are associated with differential responses to localized weather shocks in contexts where formal protection remains limited.
__________________
WP6 - Land-related institutional settings, climate variability and communal conflicts in Sub-Saharan Africa
Sara Balestri, Department of Economics, University of Perugia
Raul Caruso, Department of Economic Policy, Università Cattolica del Sacro Cuore & International Peace Science Center (IPSC) & CESPIC, Catholic University “Our Lady of Good Counsel”
Abstract
We analyse to what extent land-related institutional settings affect the likelihood of communal violence in Sub-Saharan Africa and whether this relationship is conditioned by climate variability. Using a country–year panel covering the period 1990–2024, we focus on the occurrence of communal violence and examine the role of legal transparency and predictable enforcement of laws. The empirical analysis relies on a panel probit model for binary outcomes, controlling for socio-economic characteristics, land-use patterns, demographic pressure, and conflict persistence. The results show that higher levels of legal transparency and more predictable enforcement are consistently associated with a significantly lower likelihood of communal violence. This relationship proves robust across alternative specifications and sample restrictions. To address potential endogeneity in institutional quality, we implement a set of complementary strategies to account for unobserved heterogeneity, while exploiting early post-independence institutional conditions to mitigate concerns related to reverse causality. These checks support the robustness of the baseline association. Climate variability does not emerge as an independent driver of communal violence. Instead, drought acts as a threat multiplier by conditionally weakening the conflict-mitigating effect of legal institutions. Interaction effects indicate that while improvements in institutional quality substantially reduce the probability of communal violence under normal climatic conditions, this stabilizing effect progressively diminishes as drought severity increases and becomes negligible under severe drought. Therefore, as drought severity increases, the mitigating role of institutions progressively weakens. Overall, the findings highlight the central role of legal transparency and predictable enforcement in managing land-related tensions, while showing that their effectiveness is contingent on environmental stress.
__________________
WP5 - Arms Import and Civil Conflict Onset: Risk-Set Evidence from Sub-Saharan Africa, 1960-2022
Anna Balestra, Department of Economic Policy, Università Cattolica del Sacro Cuore & International Peace Science Center (IPSC)
Raul Caruso, Department of Economic Policy, Università Cattolica del Sacro Cuore & International Peace Science Center (IPSC) & CESPIC, Catholic University “Our Lady of Good Counsel”
Abstract
Civil conflicts impose massive costs, yet their onset determinants remain contested. This paper examines whether deliveries of major conventional weapons (MCW) precipitate new intrastate violence episodes, using annual panel data for 46 Sub-Saharan African countries (1960–2022). We construct civil conflict onset on an explicit risk set - excluding ongoing-conflict years per McGrath (2015) - and model duration dependence via cubic peace-years polynomials (Carter and Signorino, 2010). The key regressor is inverse hyperbolic sine-transformed SIPRI TIV deliveries (contemporaneous plus lags), capturing realized coercive inflows. Within-country fixed effects models reveal a robust positive association: unusual delivery spikes elevate onset probability. Placebo leads yield no pre-trends; leave-one-country-out diagnostics confirm broad-based effects. Fiscal capacity enters negatively, supporting crowding-out channels. To connect with climate-related stress pathways, we control for lagged climatic anomalies using the Standardized Precipitation Evapotranspiration Index (SPEI) and its square: these aggregate country-year terms are imprecisely estimated and do not display robust direct effects on onset once fixed effects and institutional covariates are included, but their inclusion leaves the arms-onset relationship essentially unchanged. Results survive nonlinear triangulation (logit, PPML, cloglog), wild bootstrap, and permutation inference. Cumulative availability and binned exposures display monotone escalation. Findings advance Pamp et al. (2018) conditional insight - arms amplify hazard selectively in high-risk settings - via risk-set precision and Sub-Saharan identification, while suggesting that climate-conflict links may be difficult to detect in annual national panels where climatic exposure and its institutional mediation are highly heterogeneous. Policy cautions against unconditioned MCW to fragile recipients, favoring capacity-contingent restraint.
__________________
WP4 - Education and Military Spending: Countervailing Forces in Designing an Economic Policy for Peace
Anna Balestra, Department of Economic Policy, Università Cattolica del Sacro Cuore & International Peace Science Center (IPSC)
Raul Caruso, Department of Economic Policy, Università Cattolica del Sacro Cuore & International Peace Science Center (IPSC) & CESPIC, Catholic University “Our Lady of Good Counsel”
Abstract
This paper contributes to peace research by assessing the viability of an economic policy instrument for sustaining social peace. The central argument posited herein is that the ratio of public investment in education to military expenditure (henceforth referred to as Edumilex) serves as a meaningful instrument for promoting policies conducive to peace. To empirically evaluate the impact of Edumilex on peace, we construct a measure of domestic peace (henceforth referred to as Social Peace Index) structured around four core dimensions: (i) Health, (ii) Standard of living, (iii) Quality of institutions, and (iv) Spread of violence. Utilizing a panel dataset of 88 countries from 1990 to 2020, we estimate the impact of Edumilex on Social Peace Index through an IV/2SLS estimator. The findings reveal a robust and positive relationship, suggesting that Edumilex holds potential as an effective tool for economic policy geared toward peace. In addition, we document a systematic climatic dimension: hydroclimatic stress—captured by the Standardized Precipitation Evapotranspiration Index (SPEI)—is negatively associated with social peace, whereas CO2 emissions per capita (used as a proxy for development) correlate positively with the index, consistent with the climate–conflict literature emphasizing the role of climatic shocks and vulnerability (Harari and La Ferrara, 2018; Ide et al., 2021; von Uexkull et al., 2016). This proposition represents an innovative departure from traditional perspectives, as governments typically treat education and military spending as discrete policy areas. However, our results suggest this perspective may be limited, as both sectors critically impact peace. By linking these domains, this study clarifies the broader implications of balanced public spending, offering insights for policymakers on fostering stable, peaceful societies through integrated economic strategies.
__________________
WP3 - Does corruption trigger political violence? Evidence from Sub-Saharan Africa (1970-2020)
Raul Caruso, International Peace Science Center (IPSC), Università Cattolica del Sacro Cuore
Emma Galli, Sapienza University of Rome
Giulia Tringali, Sapienza University of Rome & International Peace Science Center (IPSC), Università Cattolica del Sacro Cuore
Abstract
This paper empirically investigates the relationship between corruption and political violence in 49 Sub- Saharan African countries over the period 1970-2020. Specifically, it examines whether corruption influences both the incidence and the brutality of political violence. To address this question, the study employs an articulated estimation strategy: first, we analyze the impact of corruption on political violence incidence and brutality by using count data models (Negbin and ZINB) and a LPM; then we also employ an IV estimation for the OLS model and a Two-stage Residual inclusion (2SRI) estimation. Across the different specifications, our findings highlight a strong and positive relation between political corruption and both the incidence and brutality of political violence. Control variables present the expected relations with the dependent variable and in particular, we also focus on climate change. By employing also interaction terms between SPEI and corruption, the results suggest that an increase in precipitations in corrupted countries leads to and increase of violence. In addition, our main results show that past corruption level has a great impact on today violence, while past extreme weather events do not.
__________________
WP2 - Climate Change – Agrifood – Conflict Nexus Pathways: A Scoping Review of the Literature
Donato Romano, Università degli Studi di Firenze
Luca Tiberti, Università degli Studi di Firenze
Tulia Gattone, Università degli Studi di Firenze
Raul Caruso, Università Cattolica del Sacro Cuore
Sara Balestri, Università degli Studi di Perugia
Anna Balestra, Università Cattolica del Sacro Cuore
Abstract
This paper explores the pathways linking climate change and conflict, shedding light on the critical role the agrifood system can play as an intermediary. By conducting a scoping review of recent literature (2014-2024), this paper identifies two main pathways: increased competition over natural resources used in agriculture and decreased agricultural productivity. While some relationships, such as those examining the immediate causes of conflict – like threats to livelihoods, increased migration, and food insecurity – have been extensively studied, others, such as the impact of price changes and market forces, remain surprisingly underexplored. Various empirical approaches have been employed to identify these pathways, including ordinary least squares and logit/probit regressions as well as instrumental variables and structural equation modeling. Recently, the availability of high-resolution georeferenced datasets including socio-economic, environmental and conflict data, along with methodological advancements like spatial econometrics, have prompted more detailed and rigorous analyses. Current research gaps include the paucity of empirical studies at the micro level and the insufficient exploration of how market-based mechanisms influence the dynamics between climate change and conflict through the agrifood sector. The paper discusses future research directions, emphasizing the need for multidisciplinary approaches.
__________________
WP1 - Vulnerability to Climate Change and Communal Conflicts: Evidence from Sub-Saharan Africa and South/South-East Asia
Sara Balestri, Università Cattolica del Sacro Cuore
Raul Caruso, Università Cattolica del Sacro Cuore & CESPIC
Abstract
This paper examines the influence of climate change vulnerability on the likelihood and severity of communal violence, with a particular emphasis on delineating large-scale regional patterns. Specifically, the analysis centres on Sub-Saharan Africa and South/South-East Asia - both regions being predominantly characterized by rain-fed agriculture and climate-sensitive economic activities - spanning the years 1995 to 2021. Relying on the ND-GAIN Vulnerability Index as a multidimensional measure for propensity of societies to be negatively impacted by climate change, we found robust evidence that greater vulnerability is conducive to a higher likelihood and severity of communal violence in Sub-Saharan Africa. On the other hand, in South/South-East Asia, results suggest that current climate variability, measured as rainfall deviations within the period, exerts a greater effect on communal violence outbreak than overall vulnerability to climate change. In both regions, greater access to productive means is significantly associated to the reduction of communal violence.
Last update
27.02.2026