[dag100]

How is it inaccurate? If I only care about buying apples, and apples get 10% more expensive, and my salary only increases by 5%, then I can't buy as many apples as I could have before. How many apples I do actually buy in the end is irrelevant to the calculation.

[sowbug]

The person you're replying to erroneously interpreted "stay even" as "avoid going into debt," instead of your income's purchasing power remaining constant.

[furyofantares]

Consumer price index is about consumer goods. This is why tarrifs and such are considered regressive - they hit people harder the less money they have because a larger percentage of their spending is consumer goods.

If I invest half my income and spend half my income, and the prices of goods goes up 4.2% and my income goes up 4.2%, then I've made progress; I'm now investing more than half my income, because the half of my income I was spending has stayed even and the half I was investing has increased.

[dag100]

> If I invest half my income and spend half my income, and the prices of goods goes up 4.2% and my income goes up 4.2%, then I've made progress; I'm now investing more than half my income, because the half of my income I was spending has stayed even and the half I was investing has increased.

Let's say your income is $100. You spend $50 and invest $50. The prices of goods goes up 4.2%, so to keep your current living standards, you must now spend $51.20. Your income increases by 4.2% to $104.20. After expenditures, you now have $51.20, or exactly half your income, to invest. So you haven't made any progress. And investing $50 now is equivalent to investing $47.98 before in terms of what you could have bought instead of investing.

[furyofantares]

Oh yeah, oops, thank you. (Btw 52.10 not 51.20, but yes, half of 104.20).