If your a Tech and over 40 have you peaked on compensation?

Tech Crunch has an interesting article about the level of pay Silicon Valley Tech's get paid throughout their career.  The article explains that as you start your career you are willing to be paid less and work more.  You peak earnings potential wise at around 40.  From there until you retire you will likely actually drop by almost 17%.  What I thought was kind of interesting was that they linked to another article by the same author that talked about how the average age of a entrepreneur in Silicon Vally is 40.  The second article then goes on to say that the older entrepreneur's also raise more money.  They don't seem to make the plausible leap that the reason for the drop might be that the Rock-Star and higher paid techs are very likely to be the ones confident enough to be entrepreneur's.  That would then be pulling them out of the pool and lowering the average since they would now be counted as self employed or entrepreneurs and not technical.  The two articles are good quick reads and informative.