We use bill cosponsorship and roll‐call vote data to compare legislators' revealed preferences in the U.S. House of Representatives and the Argentine Chamber of Deputies. We estimate ideal points from bill cosponsorship data using principal‐component analysis on an agreement matrix that included information on all bills introduced in the U.S. House (1973–2000) and Argentine Chamber (1983–2002). The ideal‐point estimates of legislators' revealed preferences based on cosponsorship data strongly correlate with similar estimates derived from roll‐call vote data. Also, cosponsorship activity in the U.S. House has lower dimensionality than cosponsorship has in the Argentine Chamber. We explain this lower discrimination as a function of individual‐ and district‐level factors in both countries.

Policy networks formed by co‐authoring and co‐sponsoring bills reflect one of the most important types of connection legislators develop while in office. We expect that in presidential countries, the probability of a tie between two legislators should be influenced by partisan membership, territorial linkages and the policy areas in which they develop expertise. Given the complex nature of relational data and the particular characteristics of bill initiation networks, we propose a new approach – bootstrapping an exponential graph model using augmented data reflective of the frequency of ties – to address the challenges of thinning dense networks.

Ten Latin American presidents have a power that has not received the study that it deserves: the ability to make positive suggestions to vetoed bills. These “amendatory observations” return to Congress for afinalround of voting. Sometimes the presidential version of the bill becomes the default alternative automatically and may require qualified majorities to be overturned. The authors analyze veto procedures in eighteen Latin American countries and argue that amendatory veto power significantly increases presidential weight in legislative decision making.

This paper examines the approval of government bills in Chile, evaluating the effect of presidential prerogatives and policy substance, and considering both bill-specific and contextual effects. The results show that presidential prerogatives over financial policy as well as the ability to affect the congressional agenda through urgent bill scheduling, significantly influence government bill approval. As expected, government success is enhanced during the honeymoon period. However, changes in public approval of the president do not appear to exert a significant effect on the passage of presidential bills.

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