Housing as an investment is the problem here. The cost of the houses and the cost of the rent are adjusting to the income, if you double the income in the regio

Housing as an investment is the problem here. The cost of the houses and the cost of the rent are adjusting to the income, if you double the income in the region you will have triple the rent (because the disposable income will increase much more than the actual income increase). See Silicon Valley for a good demonstration of this.