What is the aim of the tax system?

I was reading an article by Polly Toynbee recently about inheritance tax, the argument being about it being a tax on already taxed income, that people have worked hard through their lives to accumulate and the evil tax man is preventing them from giving their children a nest egg, versus a tax on the rich that hardly anyone (with a bit of advance planning) will have to pay anyway.

Which started me thinking – what is the aim of the tax system?
1. Is it a means of redistributing wealth from the rich to the poor? Toynbee says; “The top 1% of the population owns 23% of everything. The bottom 50% owns just 6%. If you take homes out of the equation, then the top 1% owns 63% of everything – the bottom half just 1%”. But if you take this aim to the extreme, then the tendency of really rich people to leave the country, and rob the tax system of their money altogether presumably increases.
2. Is it to fund public services and the political ideology of the ruling party? The current government appear to be pumping more money than ever into the political football called the NHS, yet don’t appear to be getting the results that such a large injection of cash warrants – some hospitals are in big deficit and laying off staff despite the money injection – some student nurses appear to be qualifying and then unable to find jobs. The whole system seems out of kilter, perhaps because of the relative short time between elections meaning money gets pumped in quickly without the real long term thinking required to make effective and efficient use of the cash.
3. Is it to drive our behaviour in certain directions? For example, “green” taxes. Toynbee writes: “Petrol taxes would have to be raised by 18p a litre or airline ticket taxes quadrupled (to replace inheritance tax). These might sound greenly desirable, but they would hit the least well off drivers hardest and those who use budget airlines…… (And) the main problem is that if green taxes had a deterrent effect, then the tax take would fall and other sources of income have to be found.

So, I suppose you drive your tax policy in the direction of whichever aim suits your political view. And, like many systems, there are conflicts to be considered between differing aims that have to be balanced and optimised, so far as they can be.

Leaner - A380 or Dreamliner?

I see the A380 Airbus is claiming to be greener by transporting huge numbers of people (up to 800) between airport hubs, and people making "spoke" onward journeys by smaller aircraft or other modes. The Boeing 787 Dreamliner is smaller 290 passengers, but it is claiming better green credentials in terms of litres of fuel useage per 100 passenger km, and also that it will fly people direct to the local airport, rather than the hub and spoke.

The "which is greener" debate will continue, but which is leaner? The A380 is effectively batching people and incurring waste at the hub airports (Boeing estimates that between 30% and 50% of all traffic at hub airports is just passing through, and adding to the already congested operation at such places) - whereas the Dreamliner model sees fewer delays as people travel directly to a point much closer to their ultimate destination.