103 Formally, it is necessary that the cariats of interest, here the indicator of the contract, are not correlated with the potential result, here the sustainability of an agreement, after the integration of all control variables. This is also called the acceptance of «observable selection.» By definition, if the choice between congressional contracts and executive agreements were random, the community of interest would not be correlated with the potential outcome. However, without randomization, the choice of acceptance of observables remains unverifiable and is the subject of theoretical debate. As explained in more detail in 11 FAM 721.2, there are two domestic law procedures by which the United States becomes parties to an international agreement. First, international agreements (regardless of your title, name or form) that come into force with respect to the United States only take place after two-thirds of the U.S. Senate has given their opinion and approval in accordance with Article II, Section 2, of Clause 2 of the Constitution. Second, international agreements, which come into force with respect to the United States on a different constitutional basis than the Council and Senate approval, are «non-treaty international agreements» and are often referred to as «executive agreements.» There are different types of executive agreements. Before conducting the analysis, it is important to correct any limitations of this file. Although TIF is the most comprehensive collection of international agreements to date, there is no data set listing each previous international agreement reached by the United States. Footnote 78 Researchers may try to supplement TIF with other contract collections to establish a more complete list of agreements. However, this is neither desirable nor feasible for several reasons. It is possible to understand this ambiguity in the empirical results by observing that previous studies all follow a similar approach. The researcher analyzes the environment in which an international agreement has been reached and attempts to identify models that help predict the type of instrument used.
If the model corresponds to a motivation that places different importance on the treaties and executive agreements of Congress, it is proof that these instruments differ in their quality. Thus, Martin concludes that contracts are used when the partner country has a high GDP per capita, that contracts are preferred when the stakes are high, and that they must therefore be more reliable engagement mechanisms than agreements between Congress and the executive branch. Similarly, Hathaway concludes that few commercial contracts are concluded, that the decision to use the treaty must be driven by historic conventions that have made the agreement between Congress and the executive attractive for trade negotiations.