This issue contains a symposium of six articles regarding the Stockholm International Peace Research Institute's (SIPRI) arms industry and military services database. Aude Fleurant and Nan Tian, both at SIPRI with work responsibilities for the database, introduce the symposium and the history of the database. Ron Smith and J. Paul Dunne discuss types and examples of quantitative analyses of the database. Diego Lopes da Silva proposes a method by which to estimate countries' domestic arms production volume, using SIPRI's existing methods for estimating the volume of international arms shipments. Herbert Wulf proposes expanding SIPRI's arms industry database to compare the industry's size to other industries and to countries' GDP or other summative measures of overall economic heft. Keith Hartley discusses "knowns and unknowns" regarding arms industry data and the difficulties one encounters in collecting data. Finally, Sam Perlo-Freeman discusses arms trade corruption and the systemic role governments and party politics play in this regard.