So much for the theory. The revival in mergers and acquisitions has withstood recent market volatility. However, the much-expected hike in emerging market deals has yet to make a meaningful contribution to overall deal volumes.

The value of announced global M&A deals so far this year is up by 27% from the same period last year, mostly driven by transactions in Europe and the US. As much as 70% of this year's deals involve either a US or European target, Dealogic data shows. By contrast, Asia-Pacific accounts for 20%, the Middle East and Africa for 2%, with the rest of the world comprising 8% of dealflow, according to data provider Dealogic.