International agreements are formal agreements or commitments between two or more countries. An agreement between two countries is described as “bilateral,” while an agreement between several countries is “multilateral.” Countries bound by countries bound by an international convention are generally referred to as “Parties.” 42 Hathaway, supra note 1, at 1239-40 (“Although there are models for the current practice of using either type of agreement, these models have no identifiable rational basis”). The second opportunity is that presidents can unilaterally withdraw from contracts, while the exit of the agreements on the executive branch of Congress requires the participation of Congress. Footnote 41 This would allow presidents to easily deliver on their promise even if a contract is entered through the consultation and approval process. A second limitation of this study is that, while the contracts indicate that they are considered a political instrument, they do not speak directly of the relative importance of the various assumptions for greater contract sustainability. Several mechanisms have been proposed to explain this sustainability, ranging from signal theory to the stability of senators` preferences, to the possibility that the consultation and approval process will reveal more credible information to negotiating partners. Of course, none of these statements exclude each other; Indeed, it may be naïve to think that a single theory can explain the choice between the engagement mechanisms for each agreement. However, since all the mechanisms in this analysis yield identical results, the results are not indicative for those who are interested in evaluating and comparing the relative importance of each of the proposed explanations. Nevertheless, it cannot be concluded that there is certainly no difference between treaties and ex post-Congress executive agreements. Failure to reject the zero hypothesis differs from the evidence of the zero hypothesis.
The number of ex post executive agreements in the sample is small. Therefore, the failure to reject the zero hypothesis may be due simply to large standard errors due to data scarcity. This is especially true for models (2) (5), which include a large number of covariates, resulting in data savings in many subgroups.