Total cost of public services divided by the population I suppose
A fair share could be considered as each to their ability, each to their needs.
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If so then please enlighten me as to where a bank gets the money to make a loan
Now here's an interesting question. Money used to be in gold and silver. Then the bank of England issued notes with the word "I promise to pay the bearer" on them, with the intention of giving gold to those who presented the notes. Except the notes then stayed in circulation, and became the defacto standard for money.
I suspect the real point behind your question, is where is all this electronic money going round in cyber space. When the Government did the QE trick, did they actually print the £350bn, or did they just add a few zeros to the balance sheet with a sleight of hand accounting. In theory, there should be a bank vault somewhere with all this money stashed away, but I have my suspicions.
And so "he" should be. We pay tax as a percentage of our earnings. Those who earn very little pay little tax.
Therein lies a conundrum, or maybe an anomaly. The liberals raised the tax threshold to 10K, so the percentage game kicks in above that. But whilst it was a kind and generous thing to do, it then put a greater burden on the middle classes (because the rich are obviously avoiding it according to JohnD) and the conservatives went along with it, because avoided the benefits bill growing higher. So those on low wages contribute very little to the economy, and often take more out, and that was one of the arguments during the Brexit campaign against foreign workers coming over here, because most of them were on low wages, so took out more than they put in.