The average company exiting through a public offering is more mature than a company that exits through an acquisition, at least since 2000.

There is good reason for this extra maturation. Public investors are often seeking to buy shares in companies that will continue to operate independently long into the future. In contrast, corporate acquirers may buy companies when they are very young before the company has demonstrated its ability to sustain itself. There are a variety of reasons why a company might be bought without demonstrating financial sustainability; a fledgling company might be acquired for its assets (technology, customer, contracts or management) or it may be acquired as a defensive maneuver – to eliminate the opportunity for the company to become a long-term threat.

It could also be argued that Sarbanes-Oxley legislation, which requires additional internal process documentation and oversight by public companies traded on U.S. exchanges, has delayed public offerings. Companies must ensure they will be compliant with Sarbanes-Oxley regulations, and that they can afford to pay the associated costs, before they can issue public stock for the first time.

From the period of 1996 to 2008, the average company that IPO’d was 8 months older than the average company to be acquired. It’s worth noting that this pattern didn’t hold true during the Internet boom. In the period of 1996 to 1999, the average software company making its initial public offering was five months younger than the average company being acquired (according to Dow Jones Venture One data).

The general trend of IPOs taking longer to realize than acquisition also puts pressure on investors to push for larger exit values. VCs are judged by their investors based upon a number of metrics, one of which is call the Internal Rate of Return (IRR). An IRR is an accurate way of measuring the average annual rate of return on invested capital adjusted for the timing of cash flows. A simple relationship that comes from this math is the fact that longer times to exit reduce the effective annual return. Returning 200% of invested dollars in 1 year implies a higher average annual increase in value than returning 200% of invested dollars in 10 years. As a result, the delay in exit time drives VCs to require higher exit values to adjust for the delay. While in theory the increase in value can be justified by the company’s ability to expand its operations and increase revenues over that period, every exit is ultimately a negotiation and this delay drives VCs to target higher exit values.