For example your $1000 oled tv is better than your $1000 crt tv therefore you your purchasing power has gone up. Or your base truck now comes with nav therefore your truck can be 5k more and still be net neutral. The problem with this system is that in order to stay in the same price catagory on the index you continually need to move down the product tiers. So today’s lowest tier is a decade ago mid tier is 2 decades ago high end. Moving down like that makes you feel poorer because wealth is relative.