Who is involved in mergers and acquisitions?

The acquisition of critical mass.

A firm would never set out explicitly to acquire a monopoly as it is against the public interest and illegal in most countries. Hubris is where management are overconfident about their acquisition abilities. However they are not aware that they are being over-confident and risking shareholder value. Empire building is where management are explicitly acting in their own interest at the expense of the shareholder. So in none of these cases would the reason be either legitimate or explicitly stated.*##**##*