Mechanism-SpecificManskiBounds
Alexander Tabarrok(Based on Adam Glynn, Does Oil Cause Civil War Because it Causes State Weakness?)
Graphical Model for Mechanism
State Weakness
Oil
Civil War
Oil on Civil War
Average Effect BoundsHigh bound: Suppose that in every case of oil and no war there would not have been a war without oil and that in every case of oil and war there would not have been a war without oil. 16/19*0+3/19*1=3/19.Low bound: Suppose that in every case of oil and no war there would have been a war without the oil and in every case of oil with war there would have been a war without oil.16/19*-1+3/19*0=-16/19.Bounds on oil creates war {-16/19, 3/19}, i.e. data is compatible with oil having a big reduction in war or with a small positive effect on war.
Oil on State Weakness
Average Effect BoundsHigh bound: Suppose that in every case of oil and no SW there would have been no SW without oil and that in every case of SW with oil there would have been no SW without oil. 19/28*0+9/28*1=9/28.Low bound: Suppose that in every case of oil and no SW there would have been SW without the oil and in every case of SW with oil there would have been SW without oil.19/28*-1+9/28*0=-19/28.Bounds on oil creates state weakness {-19/28, 9/28}, i.e. data is compatible with oil having a big reduction in SW or a fairly big positive effect on SW.
Average Effect BoundsHigh bound: 3/28*1+0/28*1+16/28*0+9/28*0=3/28Low bound: 16/28*-1+3/28*0+9/28*-1+0/28*0=-25/28Bounds on oil creates war through state weakness {-25/28, 3/28}, i.e. data is compatible with oil having a big reduction in War through SW or a small positive effect on War through SW.
Oil on Civil War Through State Weakness
Note something a little odd. Where is potential evidence coming from that Oil causes War through SW? Consider the row with 3 obs. We have Oil, no SW, and war. Would seem to rule against hypothesis. But notice that the bounds are from OilreducesSW &SW reducesWar thus if Oil then SW and thus War (-1*-1=1). See also row with 9 obs.Oil couldreduce or increaseSWbut suppose that we rule out that SW candecreasecivil war. What then?High bound: 0Low bound: 16/28*-1=-16/28Bounds {-16/28,0}. Thus Oil is not compatible with causing war through SW.
Monotone treatment assumption: Assume that SW cannot reduce chances of war.
Oil on Civil War Through State Weakness
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