IEA Director General is quoted in the Observer. In the article he argues that re-introducing the 50p tax band for incomes over £150,00 as proposed by Ed Balls would be a disaster to both enterprise and economic growth. This is because innovation would be disincentivised leading to less job creation.
In 2012, approximately 300,000 people were earning above 150,000, yet their contribution through income tax totaled 30 percent of all receipts taken.
You can read the full article here.