In many Member States, this aspect of enlargement has been discussed widely and the literature on this topic has been growing strongly. Many of these studies seem to suggest that overall migration flows to the EU are likely to be small relative to the size of the workforce in the EU, though large uncertainties surround these estimates.
Coming to the second channel, enlargement will lead to a widening of the Single Market and most likely to an increase in competition both for the acceding countries and for the present Member States. Taking the experiences with the Single Market as a benchmark, this could reduce price pressures (via a decrease in mark-ups) and enhance productivity (by exploiting economies of scale).