At this stage the LIS database includes about 70 datasets for 25 countries, covering the
period from 1967 to 1995. Most datasets include three different files, the first with data at
the household level (allowing sometimes also a disaggregation among multifamily
households), the second at the individual level and the third at the child level. One of the
main issues in setting up such a database is to elaborate data from single national
household budget surveys transforming variables and re-weighting single cases in order to
allow a satisfactory international comparison. Of course, perfect comparability will never
be reached but the LIS database allows a good degree of comparability between several
countries.