Martin does an empirical analysis to support the signal theory. It analyzes 4,953 international agreements concluded between 1980 and 1999 and finds that the value of the underlying relationship governed by the agreement is crucial for the use of a treaty or executive agreement by a president. Footnote 53 The value is calculated on the basis of an indicator of the multilateralization of the agreement, the contractor`s GNP per capita and the overall GNP. Footnote 54 Martin notes that presidents are particularly likely to rely on the treaty when the underlying value of the relationship is high. It concludes from these findings that the contract is reserved for highly committed negotiations, in which the Chair must demonstrate a firm commitment to the contracting parties. At the same time, the article raises new questions about the mechanism responsible for extending the validity of contracts. Empirical results suggest that a new scientific focus on this issue and on the political cost of the end of the contract provides fertile ground for broadening our understanding of the practical impact on U.S. policy of choice between treaties and congressional executive agreements. Most executive agreements were concluded in accordance with a treaty or an act of Congress. However, presidents have sometimes reached executive agreements to achieve goals that would not find the support of two-thirds of the Senate.
For example, after the outbreak of World War II, but before the Americans entered the conflict, President Franklin D. Roosevelt negotiated an executive agreement that gave the United Kingdom 50 obsolete destroyers in exchange for 99-year leases on some British naval bases in the Atlantic. 75 This decision is based on the rationale that the President-in-Office has the most influence on its content at the time the agreement was signed. However, the content of all results is the same when a categorical variable is used for the president under whom the agreement came into force. Relevant regressions are included in the online schedule. 101 Note that the analysis only takes into account agreements reached between 1982 and 2000 to take into account the fact that ex post-congressional-executive agreements are not identified beyond that period.