When silicon valley execs collude to lower wages, there's effectively one employer for high tech workers; and in a monopsonistic labor market, raising wages doesn't reduce employment, it actually increases employment, increases output and lowers prices--something that's easy to prove by drawing supply and demand curves and considering what happens when we start off with the price of labor below the equilibrium price, and then increase it up to the equilibrium price.

However, silicon valley jobs aren't the same as minimum wage jobs: McDonald's and Burger King aren't colluding and agreeing not to hire each other's workers and so forth.

Moreover, when NJ raised its minimum wage in 1992, what happened was (1) employment increased, and (2) prices increased. This observation fits neither the competitive nor the monopsonist model! These observations were made by David Card and Andrew Krueger.

A resolution for the "Card-Krueger Paradox" was developed by A. Ross Shepherd, Professor Emeritus of the University of Missouri--Kansas City and Published in the Southern Economic Journal on Oct 1, 2000. There's a copy online here (but it lacks the figures): http://www.thefreelibrary.com/Minimum+Wages+and+the+Card--Kr...

His solution boils down to realizing we have an impure monopsonistic market in which the higher minimum wage increases the firm's Long Run Average Cost. So employment goes up, but so do prices.