The market has been driving the poor and the working class out of these cities ever since, and the Innovation Economy is finishing them off, cleaning house for the new guests. The cost of housing in Cambridge and Greater Boston has zoomed, with rising rents taking a growing share of dwindling low- and middle-incomes. Partly by design, partly by accident, the corporate consolidation of the housing stock will wind up leaching diversity from neighborhoods by pricing residents out and installing corporate professionals in their place. Innovation means the price of existing goes up.