Power corrupts, according to the 19th century historian Lord Acton – but sometimes concentrating power in the hands of the few is inevitable.

The asset management industry is still fragmented, but it is consolidating in the wake of the financial crisis. BlackRock's acquisition of Barclays Global Investors closed last week, and the newly merged $2.8 trillion (€2 trillion) asset manager will be the largest in the world. At the end of 2008, the two companies had a 10% share of global institutional assets between them, according to US financial publication Pensions & Investments.