Again with the acerbic condescending tone, eh? Now-now, play nice with the other kids.
...I don't know about all the stuff you've listed above - the point is, your example doesn't work if your take home salary is more than 100k USD. And additionally, if you are adjusting your 200k USD for taxes, you need to adjust your 80k GBP as well.
I suspect the first sentence is the problem. You're not hearing the difference between "salary" and "income". Understandably as we all, myself included, tend to use the two words inchangeably. However, and as any economist will also tell you, they are not one and the same. I won't bore you and everyone else with dissertations on it. It's quite dry stuff, honestly.
But at the simplest level, gross business income is pre-business expenses; the corp. earns the income; then pays its expenses; what's left is business net income. In a C corp, the net income (after business expenses), is then transfered to personal gross income. At which time, it can then be subjected to further tax deductions. DH can take as little or as much as it likes. (The rest stays in the corporation as a business asset.)
He takes $100,000. And no, he won't/can't/doesn't have to apply the same principle to UK "salary" because their laws are not the same. The only common ground is how the net $100,000 will compare to the offered £80,000 "salary".
That is the point at which both the US and the UK begin to adjust for fed/state taxes, FICA, NIN taxes, etc. (See, told ya it's dry stuff!

)
Yes - for you...And I fully understand that this is YOUR example and YOU might be better off in the UK...
And that's what I've been saying all along. Phew!
I disagree - you and your husband ARE a special case. Not many people will be making the kind of money you are, and not many will be significantly downsizing their lives the way you are. As you and your husband have lived in so many different cities, you will appreciate that it costs more to live in some places than others.
Have to strongly disagree there. I suspect it's more accurate to say that not many people making the kind of money I'm talking about will ever want to admit it on this forum. (I only first put forth our own because it was necessary to be specific to get the answer to a troubling visa question. Thank you Ms. Vicky! And now to use as an example for others who may be puzzled with the same issues, as I don't imagine that I'm unique in the US-to-UK immigration thing.)
But there are people on this very forum who do or will earn a similarly high UK salary. US inter-corporate transfers come immediately to mind. I've read threads on here by some who've heretofore been quite reluctant to say so (as I was) for fear of this very sort of consternation. It stands to reason that if £45k salary is an expected norm, (as I believe someone stated earlier) then if both hubby and wife are similarly employed, then household income is actually £90k. That's more £10k more than the £80k I used.
Cost of living is measured by how much something costs in any given place.
Then surely you'll agree that I've
increased/increased my exposure to high-cost living by plopping myself down in a rented flat in the city center, rather than buying a house in the 'burbs? That's more expensive, not less so. And, don't forget I'm building 0 equity to contribute towards my personal wealth. Rather, that expense comes straight off the bottom line of my net worth. And yet,
for me that cost of inner city housing and its attending upkeep will be cheaper on my monthly outlay
for me.
A given item in the UK will generally be cheaper in the US. That's a fact. Not everything, and not everywhere. But in general - it will.
Emphasis is mine. And exactly my point.
Why do most people on this forum do loads of shopping when they're in the US? Why do the British take shopping holidays in New York and come back with suitcases full of things? Because it's cheaper there!
Quite so, at least where clothing is concerned, (other items I find to be much friendlier to my wallet), which is why I doubled my outlay for the UK from $200/per month pro rata to £400/per month pro rata. Overkill perhaps, but still it doesn't kill the cost-of-living grand total.
No one is discounting anyone's experience (other than disputing some of the quoted numbers), and of course everyone's situation is different.
And yet, Vicky's (a native Uk-er's) numbers bare me out.
But the original point being discussed was whether cost of living is higher or lower in the UK. And the answer is that it's higher.
Actually, the original point here (excluding our hijacking of the OP's topic of "The British Pound" exchange rate) was put forward by the poor girl who said she finds that for her, living in the UK was no more expensive overall than living in the US. IIRC, she was not a homeowner in either country. She's long since disappeared from this thread, no doubt, too uncomfortable with the subsequent ire of replies. Shame, really, as I suspect it also put other guests off from speaking, as well. And the answer is, to quote you, "...not everything, and not everywhere...and of course everyone's situation is different. Of course living in London can be cheaper for you or for anyone else."