The study seems to be looking at the relative distribution of wealth, in which case the conclusion is just another way of saying that more and more income is be

The study seems to be looking at the relative distribution of wealth, in which case the conclusion is just another way of saying that more and more income is being captured by the wealthy. Older people in any generation are going to tend to be in the higher percentiles of wealth, so a general trend in wealth distribution from the poor to the rich will tend to favor them and disfavor the young. No need for rationalizing based on millenials' character, or even their micro-economics. The simple mathematical fact is that capitalism, absent some correctional force like progressive taxation, trends inevitably toward greater wealth and income disparity between rich and poor. It's built into the system; not a bug, but a feature.