some authors have suggest that only certain types of studies qualify as 'truly' comparative. Hantrais and mangen (1996b:1), for example, argue that, in order to be genuinely comparative, a cross-national research study needs to involve data being collected on certain issues or phenomena from two or more countries, 'using the same research instruments'. with the express intention of then comparing that data within a cross-national research team. this book adopts a more expensive definition, whereby any research which either explicitly or implicitly contrasts policy processes, outputs or outcomes from one or more units counts as 'comparative public policy'. Under this expensive defintion, cross-national research qualifies as genuinely 'comparative' , even if it is based entirely on secondary analysis of research produced by separate nationally-based researchers