I would like to know more about this theory. For instance, why is it that we are just now noting an increase in the income gap when it looks like income from housing has been steadily increasing for the last 62 years and other income is all over the place. The curve of the income gap is more exponential shaped, where as the housing curve above is flat. I would agree with the conclusion that housing costs have out paced the rise in income for the Middle Class, but I don’t see from this graph that there is enough data to support this as the main cause of the income gap. I would like more information.