Table 4: Robustness of interaction terms: Natural resource endowment variable * Weakness of the state Summary of regression results in Tables 1, 2, 3, SI.1, SI.2, SI.3 Table 4.1 Natural resource endowments _aggravating_ the risk of civil conflict

|||**Fearon and Lai**<br>|**tin(2003) civilwar **<br>|**Prio \ U**<br>|**ppsala civilwar**<br>|
|---|---|---|---|---|---|
|||Models with an<br>interaction coefficient<br>sign in the expected<br>direction / out of total|Models with a statistically<br>significant interaction<br>term / out of total|Models with an<br>interaction coefficient<br>sign in the expected<br>direction / out of total|Models with a statistically<br>significant interaction term / out<br>of total|
|Oil endowment measures (7)|Governance & riot<br>history|12 out of 18 models|5 out of 18 models|13 out of 18 models|6 out of 18 models|
||Social structure|10 out of 12 models|4 out of 12 models|6 out of 12 models|4 out of 12 models|
|Diamond endowment<br>measures (3)|Governance & riot<br>history|8 out of 9 models|1 out of 9 models|8 out of 9 models|1 out of 9 models|
||Social structure|6 out of 6 models|0 out of 6 models|2 out of 6 models|0 out of 6 models|
|Quantities / values of natural resource<br>endowments (5)|Governance & riot<br>history|10 out of 15 models|8 out of 15 models|12 out of 15 models|5 out of 15 models|
||Social structure|7 out of 10 models|3 out of 10 models|7 out of 10 models|2 out of 10 models|

Note: The models in Table 1.1 include the following variables for weakness of the state: governance indicators - anocracy, political instability, and riot history; and social structure indicators - ethnic fractionalization and the size of the excluded groups. As detailed in the text of the paper there are six measures for oil endowments based on Fearon and Laitin (2003), Humphreys (2005 – production and reserves), Lujala (2010 on-shore and off shore oil) and Ross (2009); three measures for diamond endowments are based on Lujala et al. (2005 – primary and secondary diamonds) and Humphreys (2005); the quantities / values of natural resource endowments include the measures from Fearon and Laitin (2003), Humphreys (2005) and Ross (2009). Humphreys (2005) oil reserves per capita are included in the estimated models.

Table 4.2 Natural resource endowments _mitigating_ the risk of civil conflict

||**Fearon and La**|**itin (2003) civil war**|**Prio \ Up**|**psala civil war**|
|---|---|---|---|---|
||Models with an interaction<br>coefficient sign in the expected<br>direction / out of total|Models with a statistically<br>significant interaction term / out of<br>total|Models with an interaction<br>coefficient sign in the expected<br>direction / out of total|Models with a statistically<br>significant interaction term / out of<br>total|
|Oil endowment measures (6)|13 out of 15 models|1 out of 15 models|12 out of 15 models|6 out of 15 models|
|Diamond endowment<br>measures(3)|7 out of 9 models|4 out of 9 models|7 out of 9 models|1 out of 9 models|
|Quantities / values of natural resource<br>endowments(4)|12 out of 12 models|1 out of 12 models|11 out of 12 models|4 out of 12 models|

Note: The models in Table 1.2 include the following variables for weakness of the state: coup d’état risk, history of coups and military regimes. The oil measures do not include the Humphreys (2005) oil reserves per capita, as it make little sense to test hypotheses based on rent distribution using measures of reserves.

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