There is a simple explanation of hedonics in the video I supplied and I offer a “readers digest version of that here:
Imagine a tv cost $300 last year, but this years model has a sharper screen. The Government says that makes it worth $100 more, even though it is still sold for $300. So the government says that the GDP went up $100 for every set sold, even though the price is the same.
So, you say, that means the CPI went up $100 too, right?
Nope. Now that you are getting a $400 set for $300, it means the price went DOWN by $100.
So, GDP is up $100 while CPI goes DOWN $100 when, in fact, no money difference occurred at all.
This means that they can show that the economy grew (good news) while the CPI was lowered. And that means Social Security, wages and other benefits which see increases triggered by CPI increases will not increase.
I have not taken the stats seriously for some time.