In modern democracy, voters should be able to use elections to control parties and politicians. Citizens lose control when their electoral voice does not compel them to act according to the will of the people. Repeated free and fair elections are supposed to function as a mechanism of electoral control. To evaluate electoral control, citizens need the right data on candidates, parties, and parliamentarians. In this edited book, we present a step towards electoral control by presenting the methodology of the East European Parliamentarian and Candidate dataset (EAST PaC). These data are the universe of candidates and parties who stood for national parliamentary elections in Ukraine, Poland, and Hungary from the 1990s to the 2010s. Candidates are matched over time, rendering a dataset that allows researchers to track the political careers of every candidate, from the thousands who never won to the few political lifers whose parliamentary careers are decades long. With EAST PaC, we can achieve new insights into electoral politics of Central and Eastern Europe. This book contains everything that scholars need to use EAST PaC. We designed the book for regional specialists and non-specialists; for seasoned scholars of representation, accountability, and political inequality, and for those who are newly interested in these concepts. We hope to intrigue potential users of EAST PaC and to attract new scholars to study electoral politics in Ukraine, Poland, and Hungary. This book is funded by Poland?s National Science Centre (Sonata Bis decision number 2012/05/E/HS6/03556).