- B.S. – United States Military Academy, 1968
- A.M. – Stanford University, 1970
- Ph.D. – Stanford University, 1979
- Trade Does Promote Peace: new Simultaneous Estimates of the Reciprocal Effects of Trade and Conflict. Journal of Peace Research, 2010. With Havard Hegre and Bruce Russett.
- Do Hegemons Distribute Private Goods? A Test of Power-Transition Theory. Journal of Conflict Resolution, 2007,With Margit Bussman.
- Does the Diversionary Use of Force Threaten the Democratic Peace? Assessing the Effect of Economic Growth on Interstate Conflict, 1921-2001. International Studies Quarterly, 2006. With Jaroslav Tir.