If you get a £3k (before tax) payrise you'll work out how to spend £3k of it, and end up worse off as you haven't accounted for the extra tax you'll be paying.
Or, put another way, if you get a £3k (after tax) payrise you'll work out how to spend £4k of it.
Exactly.
If you get a £3k (before tax) payrise you'll work out how to spend £3k of it, and end up worse off as you haven't accounted for the extra tax you'll be paying.
Or, put another way, if you get a £3k (after tax) payrise you'll work out how to spend £4k of it.