How did the Single European Act create economic gains in the EU?

What will be an ideal response?

It was predicted that there would be more trade, lower price mark-ups, increased concentration of firms due to the ability to take advantage of scale economies, and increased price convergence. Trade among EC partners rose from 61.2 percent of the total trade of member states to 67.9 percent between 1985 and 1995. The percent of total output in each industry that is produced by the four largest firms rose in most industrial sectors. The share of world mergers and acquisitions that took place in Europe rose. It is estimated that between 300,000 and 900,000 more jobs were created, and GDP in 1994 was 1.1 to 1.5 percent greater than it would have been without the measures taken to implement the SEA and the SMP. Also, income levels began to converge, as the per capita incomes of the low-income European countries began to rise toward the average.