This paper compares different approaches to measuring changes in repla
cement rates in Ireland over time. Results based on microsimulation mo
delling suggest that the average replacement rate facing unemployed pe
rsons was roughly constant between 1987 and 1994, with a small rise fo
r those on Unemployment Assistance offset by a decline for those on Un
employment Benefit. The mean predicted wage facing the unemployed is a
bout two-thirds of the average industrial wage. Time-series constructe
d using average expenditure per unemployment compensation recipient an
d average earnings do not accurately reflect changes in mean replaceme
nt rates. In addition to providing a better measure of the overall tre
nd in replacement rates, microsimulation modelling provides a picture
of their distribution, showing that the incidence of cash replacement
rates over 80 per cent fell between 1987 and 1994 but the numbers faci
ng rates between 70 and 80 per cent rose.