Shannon P. Carcelli

Research shows that foreign aid is most effective when it is centralized and streamlined, but aid advocates complain that countries waste billions of dollars on redundant and often counterproductive foreign aid tools. Is foreign aid policy really more fragmented than ever? And what explains changes in fragmentation over time? This dissertation employs a novel dataset to measure domestic-level foreign aid fragmentation and offers a domestic-politics explanation for the phenomenon, building on theories of American political institutions.

I develop a novel theory of fragmentation as a byproduct of legislative vote-buying. Fragmentation, like other forms of distributive politics, reflects a relatively weak agenda setter’s attempt to convince fence-sitters to support a piece of legislation. I hypothesize that fragmentation should be at its highest when (1) majority-party leadership is weak and (2) few opportunities for bipartisanship exist. I later extend this model to examine substitutability in methods of congressional vote-buying, an effort the distributive politics literature has not attempted.

I measure budget fragmentation over time using a new dataset of US Foreign Operations Appropriations Bills from 1961 to 2015. I test the theory on these data, finding support for the proposed mechanisms. I supplement these statistical tests with qualitative evidence that I gathered conducting elite interviews, as well as reading and coding congressional hearings, debate transcripts, and legislation. I conclude that US foreign aid fragmentation can be largely understood by considering the constellation of policy preferences both between and within parties and branches of government. When congressional agenda-setters are hard-pressed to form a voting coalition, fragmenting a bill may often be necessary in order to pass foreign aid legislation.


I am a researcher for the Center for Peace and Security Studies (cPASS) at UC San Diego. As part of an active research agenda, I have contributed to the center through publications and working papers in several areas.

My work on nuclear weapons led me, along with my coauthors, to create a novel dataset of worldwide nuclear arms treaties. In a data paper previously presented at the International Studies Association (ISA) annual meeting, my coauthors and I examine the relationship between a state's embeddedness in the nuclear arms regime and the nuclear assistance it receives. We consider when and how international institutions can serve as signals of state intent.

I have also published two separate articles to the Oxford Research Encyclopedia, reviewing both the use of signaling in foreign policy, and recent geopolitical and empirical changes in the study and practice of deterrence.


In addition to my dissertation and cPASS work, I have published and presented on other political science topics, including the impact of prenatal androgen on social network structures and the determinants of foreign military intervention.