Since the mid-1990s the strategic rollup has been a corporate fad: Large acquirers buy smaller players in fragmented industries, reaching for critical mass, McDonald's-like uniformity and that beloved state of bliss called synergy.

FORBES: Which Conglomerators Are the Big Winners?

Since the mid-1990s the strategic roll-up has been a corporate fad: Large acquirers buy smaller players in fragmented industries, reaching for critical mass, McDonald's-like uniformity and that beloved state of bliss called synergy.

FORBES: Which Conglomerators Are The Big Winners?

Some of the worst-hit industries are still highly fragmented.

ECONOMIST: The fine art of being prepared

Few other industries concentrate such a massive, fragmented supplier base in a few big buyers.

ECONOMIST: Seller beware

Whether because of national pride, incompatible priorities or the desire to prop up domestic industries, European defence spending is fragmented and duplicative.

ECONOMIST: The state of NATO

As a result some industries, especially labour-intensive ones such as retailing, stay fragmented and inefficient.

ECONOMIST: The informal economy is neither small nor benign