Conflict data. We conduct cross-country analysis to examine the impact of a macroeconomic shock on the intensity of conflicts. The main dependent variable in the regression analysis is the intensity of conflict, as measured by the number of conflict events per one million people. Conflict data rely on the Uppsala Conflict Data Program Georeferenced Events Dataset (UCDP GED) (Sundberg and Melander, 2013). It records all individual conflict events that are defined as organized violence. Conflict events are incidences of the use of armed force by an organized actor against another organized actor, or against civilians that result in at least one direct death. We use the total number of conflict events, including state-based conflicts in which incidents take place between two parties and at least one is the government of a state; non-state-based conflicts between two parties neither of which is the government of a state; and one-sided conflicts in which armed force is used by the government of a state or by a formally organized group against civilians. 6 By contrast, the data does not include non-organized or non-violent incidences, such as protests, riots, and violence by civilians. The UCDP GED contains events for all dyads7 and actors that have surpassed the 25 deaths threshold at least in 6 We find that each type of conflict events displays similar responses to a commodity ToT shock. 7 A dyad is defined in the UCDP GED as a pair of two opposing actors. In a state-based conflict, a dyad is composed of two actors, at least one of which is a government. A dyad in non-state conflict involves two organized armed actors, neither of which is a government. In one-sided conflicts, UCDP does not consider opposing actors a dyad, but rather an armed actor attacking the civilian population. INTERNATIONAL MONETARY FUND 11 one calendar year. The information is based on global news reports found using search strings run through the Dow Jones Factiva aggregator. The data cover the period from 1989 to 2021. Our dataset contains 133 countries, excluding high-income countries according to the World Bank’s GNI per capita classification (above USD 12,535 in 2020). The list of countries is presented in Annex I. We aggregate the number of conflict events by country and year. We remove the top one percentile of observations of each variable as outliers, on the premise that extremely intensive conflict episodes (e.g., Rwanda in the 1990s) are likely not driven by economic channels applicable to most countries. We normalize the number of conflict events per one million people in the population to account for country size. Mueller (2016) and Novta and Pugacheva (2021) highlight that per-capita measures are arguably most relevant from a macroeconomic perspective, as absolute numbers skew the sample toward large countries. This is particularly relevant for our analysis as countries with relatively small populations often suffer intensive conflict. 8 We complement the analysis by using the number of fatalities per one million people caused by conflicts as an alternative dependent variable measuring the intensity of conflict, obtaining similar results. Furthermore, to better understand how macroeconomic shocks affect different stages of conflict formation, we investigate entry and continuation of conflict dyads. Details are presented in Section IV. Figure 3 displays a snapshot of the global landscape of conflict events for 2021. Conflict events were mostly concentrated in Sub-Saharan Africa, the Middle East and Central and Latin America, with the highest intensity of conflicts occurring in Afghanistan. Mexico, Syria, Yemen, Somalia, the Central African Republic, Cameroon and Mali all recorded more than 50 conflict events per one million inhabitants. Figure 3: Number of Conflict Events per one Million Inhabitants, 2021 Source: UCDP GED. Commodity terms-of-trade. A key identification challenge for exploring the impact of macroeconomic shocks on conflicts is to control for endogeneity since there is ample empirical evidence in the literature (see Section II) showing that macroeconomic conditions are affected by violence. To overcome this endogeneity concern, we 8 Novta and Pugacheva (2021) report that per-capita conflict measures have significant effects on macroeconomic variables whereas absolute figures do not. Likewise, we find that the absolute number of conflict cases increase, but not significantly, in response to a negative commodity ToT shock. INTERNATIONAL MONETARY FUND 12 resort to an exogenous variation of income using the country specific commodity terms-of-trade (ToT) index, constructed by Gruss and Kebhaj (2019) and maintained by the IMF Research Department.9 The commodity ToT index covers 182 economies and provides estimates for the gains and losses in income associated with changes in international commodity prices. Specifically, the index uses 45 world commodity prices from the IMF Primary Commodity Price database classifiable under the following four categories: 1. Energy: coal, crude oil, and natural gas. 2. Metals: aluminum, copper, gold, iron ore, lead, nickel, tin, uranium, and zinc. 3. Food and beverages: bananas, barley, beef, cocoa, coffee, corn, fish, fish meal, groundnuts, lamb, olive oil, oranges, palm oil, poultry, rapeseed oil, rice, shrimp, soybean meal, soybean oil, soybeans, sugar, sunflower seed oil, swine meat, tea, and wheat. 4. Agricultural raw materials: cotton, hard logs, hard sawnwood, hides, natural rubber, soft logs, soft sawnwood, and wool. For every country in our sample, each commodity price in the index is weighed by its share in total net exports scaled to GDP to proxy its impact on aggregate income. Using net exports ensures that the effect of price changes for both exports and imports on GDP are accounted for: a one percentage point change in the index represents the equivalent percentage point change in GDP expected for each country due to net commodity price changes. The country-commodity level trade data is sourced from the United Nations Comtrade Database. The shares are built with three-year rolling averages for trade values, so that the index tracks changes in a country’s industrial structure over time. Since the weights are lagged, changes in the index should reflect changes in international prices rather than possibly endogenous responses in trade volumes. It is worth noting that the commodity ToT index is different from a standard ToT measure as it accounts for the share of each export and import good in a country’s economic structure. Gruss and Kebhaj (2019) compare the impact of the commodity ToT index and a standard ToT on macroeconomic variables and report that only the former influences macroeconomic aggregates in a statistically significant way. Figure 4 presents the commodity ToT index for the sample countries with the highest gains and losses from commodity price changes in 2021. The figure shows that there is significant variation in ToT changes within and across regions. For example, within the Middle East and North Africa region, oil-exporting countries like Qatar, Kuwait and Libya experienced a positive change in their terms of trade, while other countries such as Jordan and Djibouti suffered significant losses. It is also worth noting that the changes in the index vary considerably even across oil exporting countries due to their different net export shares relative to GDP and the impact of price changes for other commodities. 9 The latest data is available at: https://data.imf.org/?sk=2CDDCCB8-0B59-43E9-B6A0-59210D5605D2. INTERNATIONAL MONETARY FUND 13 Figure 4: Commodity Terms of Trade in Selected Countries, 2021 (year-on-year change, percent) Other economic and political variables. Our study relies on a variety of economic and political indicators used as alternative dependent measures, control variables, and, importantly, to investigate the significance of macroeconomic effects in a variety of contexts. Missing values are imputed using the previous or subsequent year’s observations to maintain sample size. Details on each variable are presented in the respective section. A full table of variables and sources can be found in Annex II. Descriptive statistics. Table 1 reports summary statistics for our dependent conflict variables, independent variables, and some economic characteristics that we explore in the results section. Between 1989 and 2021, there are 4,412 observations for 133 countries. The average number of conflict events per year per country in our sample is 3.19 per one million people, with 51.7 resulting fatalities per one million people. 10 Notably, conflict intensity differs significantly by a country’s income level. Low-Income Countries and Lower Middle-Income Countries (GDP per capita below US$4,045 in 2020) experienced an average 3.98 conflict events per one million people, resulting in 75.06 fatalities per one million people. This compares to 1.95 conflict events and 14.83 fatalities, respectively, for Upper Middle-Income Countries. Entry and continuation of conflict dyads are also higher for Low-Income and Lower Middle-Income Countries. The table also includes summary statistics for the commodity ToT index, the independent variable for this study. The index is normalized to 100 in 2012 and fluctuates between a loss of about 10 percent of GDP and a gain of 8 percent of GDP between the tenth and ninetieth percentiles. Regarding other economic variables, given our sample of Low- and Middle-Income Countries, we see on average high levels of food insecurity and high unemployment rates (37.82 percent and 8.75 percent respectively). Readings on other variables are very diverse, reflecting the variety of economies included in our sample. 10 Standard deviations of conflict variables are high reflecting a few extremely severe conflict episodes. We exclude these outliers in the regression analysis by removing the top 1% of observations, as noted above. INTERNATIONAL MONETARY FUND 14 Table 2 reports pairwise correlations among conflict-related variables, commodity ToT, and other economic variables. While a causal investigation is left for Section IV, the table presents several noteworthy facts. First, different conflict measures are positively correlated with each other, reflecting the close relationship among the number of conflict events, fatalities, and the evolution of conflict dyads. Second, the negative correlation between conflict variables and GDP per capita confirms a well-known association of conflict and income. The commodity ToT index is also negatively correlated with conflict variables, suggesting that deterioration of commodity ToT is associated with high intensity of conflict. Third, food insecurity and external debt are mostly positively correlated with the various measures of conflict. The Gini coefficient (a measure of inequality) and the unemployment rate are negatively correlated with all measures of conflict. These suggest the relevance of inequality and fiscal indicators for the occurrence of conflicts. At the same time, these indicators are clearly correlated with GDP per capita, which suggests a need for rigorous econometric analysis to identify the various statistical relationships. Table 1. Descriptive Statistics VARIABLE Observatio ns Mean Median Standard Deviation 10th percentile 90th percentile Number of conflict events (per million population) 4,412 3.19 0.00 32.54 0.00 3.31 Number of fatalities (per million population) 4,412 51.74 0.00 1392.17 0.00 32.82 Number of new conflict dyads 4,765 0.90 0.00 2.22 0.00 3.00 Number of continuing conflict dyads 3,232 1.08 0.00 2.45 0.00 3.00 Commodity ToT index 4,072 100.23 101.59 10.07 90.65 107.95 Low-Income and Lower Middle-Income Countries Number of conflict events (per million population) 2,696 3.98 0.00 34.78 0.00 4.95 Number of fatalities (per million population) 2,696 75.06 0.00 1774.51 0.00 56.70 Number of new conflict dyads 3,049 1.17 0.00 2.58 0.00 4.00 Number of continuing conflict dyads 2,336 1.21 0.00 2.69 0.00 3.00 Commodity ToT index 2,585 100.33 101.66 9.27 91.55 107.71 Upper Middle-Income Countries Number of conflict events (per million population) 1,749 1.95 0.00 28.38 0.00 1.67 Number of fatalities (per million population) 1,749 14.83 0.00 183.87 0.00 4.60 Number of new conflict dyads 2,092 0.36 0.00 1.14 0.00 1.00 Number of continuing conflict dyads 992 0.70 0.00 1.56 0.00 2.00 Commodity ToT index 1,611 99.87 101.28 11.33 88.04 108.42 Other Economic Variables GDP per capita (US$) 4,196 2,710.29 1,576.14 2,901.54 331.82 6,955.94 Gini coefficient 4,026 41.39 40.50 8.29 31.70 53.40 Unemployment rate (percent) 4,290 8.75 6.90 7.13 1.80 19.03 Food insecurity (percent of population) 2,574 37.82 36.50 22.18 11.20 72.50 External debt (percent of GDP) 4,323 62.03 42.56 77.63 -7.67 119.70 Fiscal balance (percent of GDP) 4,521 -2.77 -2.31 14.36 -37.59 2.73 INTERNATIONAL MONETARY FUND 15 Table 3 shows correlations of the commodity ToT index and its sub-categories, including the 4 broad categories mentioned above (food and beverages, raw agricultural materials, base metals, and energy), as well as crude oil. Interestingly, the correlations between the sub-categories and the ToT index are quite low (last row). While individual export and import price indices are highly correlated with individual commodity prices, the construction of the ToT index nets out the effects on the export and import sides, leaving the index specific to individual economies to reflect their net export structure. In other words, the dynamics of the ToT index capture a country’s income gains and losses, rather than just tracing the underlying commodity price fluctuations.Figure 5 shows how income shocks are expected to affect the incidence and intensity of conflicts via three channels outlined by the literature: (i) opportunity costs; (ii) state capacity; and (iii) predation. Table 2. Correlations N. of conflict events N. of fatalities N. of new dyads N. of cont. dyads Commod ity ToT index GDP pc. Gini coeff. Unemp. rate Food insecurity External debt Fiscal balance N. of conflict events 1 N. of fatalities 0.4946 1 N. of new dyads 0.2009 0.1557 1 N. of cont. dyads 0.2925 0.1154 0.6523 1 Commodity ToT index -0.121 -0.2014 -0.1335 -0.0369 1 GDP pc. -0.089 -0.0882 -0.119 -0.0187 -0.0152 1 Gini coeff. -0.02 -0.0132 -0.1117 -0.0386 -0.0292 0.1658 1 Unemp. rate -0.026 0.0115 -0.1244 -0.1481 -0.1989 0.1564 0.1826 1 Food insecurity 0.1017 0.1462 0.1473 0.0727 -0.0706 -0.3676 0.3016 -0.0544 1 External debt 0.156 0.2379 0.069 -0.0154 -0.2255 -0.2378 -0.0297 0.0315 0.1398 1 Fiscal balance 0.0189 0.0023 -0.0015 -0.0037 -0.0962 -0.0058 0.0475 0.038 -0.0055 -0.0634 1 INTERNATIONAL MONETARY FUND 16 Figure 5: Potential Channels of ToT Shock Effects on the Incidence and Intensity of Conflict Commodity price shocks can affect the opportunity costs of engaging in conflict activities. A negative commodity export price shock would lower household income, thus incentivizing households to engage in conflict. Case studies suggest that such a mechanism influenced the outbreak of the First Ivorian Civil War in the 2000s (Woods, 2003; McGuirk and Burke, 2020). In the 1980s and 1990s, Côte d’Ivoire experienced a persistent decline in the price of coffee and cocoa exports – products on which its economy relied heavily. The decline led the state and individual producers to expand their production to compensate for lower revenues. This resulted in competition over land that could be cultivated and the rise of ethnic and religious tensions, which promoted the context for the war. On the other hand, commodity import price increases reduce households’ real income, which also lowers opportunity costs. Schneider (2008) examines news reports and finds that food price increases in 2007 and early 2008 led to the eruption of food riots in more than 20 countries. The effect of a negative commodity ToT shock working through the state capacity channel is also expected to increase conflict intensity. A negative export price shock may lower government revenue, while import price increases may increase the fiscal cost of measures such as subsidies to support the population. In both cases, the state’s ability to mitigate the economic shock is weakened. For example, Sayne and Hruby (2016) describe that in Nigeria, Africa’s largest oil producer, falling oil revenue due to the oil price slump in 2014 and 2015, compounded by lower investor confidence and exchange rate volatility, constrained the government’s resources to address the expansion of Boko Haram in the northeast regions of the country. Finally, a negative ToT shock resulting from lower export prices would lower the gains to be made through rent capture, thereby decreasing incentives for conflict through the predation channel. Previous studies often report the significance of this channel for the oil and other natural resource sectors (e.g., Ross, 2004). Given the different expected direction of effect, the overall impact of commodity price changes on conflicts is ambiguous ex ante and requires careful regression analysis.