Catherine Murphy (Kildare North, Social Democrats) | Oireachtas source

From the perspective of somebody who is self-employed and employed, when that is mixed, an S stamp and an A stamp cannot be amalgamated for the purposes of pension. The employee will have to go with one or the other. If someone spends 20 years of their working life on an S stamp and 20 years on an A stamp, they really only have 20 years. There can be a considerable disadvantage in mixing employment and self-employment from the point of view of pensions.