Snakes and ladders: The development and multiple reconstructions of the Stockholm International Peace Research Institute’s military expenditure data

The Stockholm International Peace Research Institute’s military expenditure database is the only long-run, consistent dataset on military expenditure with global coverage. Even though SIPRI’s military expenditure data collection dates back almost to the organization’s beginning in 1966, until recently, consistent data series for most countries have only been available as from 1988 onward. As this article discusses, the history of SIPRI’s military expenditure project includes a number of breaks, the result of staff transitions and failures of record-keeping. As a result, reconstructing the data has been necessary on a number of occasions. The most recent such effort has now succeeded in extending the data backward from 1988 for the great majority of countries—in most cases at least to the 1960s, and for some countries as far back as 1959. This article sets out this history of advances, setbacks, and reconstructions and the methodologies used. In particular, the results of the latest reconstruction effort are presented, and thoughts for future developments laid out.