The downgrading of the UK's AAA credit rating is not only a bitter blow to the UK economy but has torpedoed one of the key arguments of those opposing Scottish independence.

We have for years been told of the merits of being in the UK due to its credit rating, but this bubble has been burst.

Contrast this with the news that investment in North Sea oil and gas is at a 30-year high, with companies looking for offshore energy investing £11.4bn in 2012, a figure set to rise to £13bn this year.

The number of projects submitted to the Department of Energy and Climate Change and given development approval almost doubled between 2011 and 2012, and there are still 24 billion barrels of oil to be recovered with an estimated wholesale value of £1.5 trillion.

Scotland is shackled within a declining UK that is gobbling up our black gold to fill a black hole in the UK Treasury. Until we in Scotland have the confidence to control our own affairs, we only have ourselves to blame for this depressing situation.

Alex Orr

Edinburgh

Timothy James (Letter, 21 February) bemoans Alex Salmond's lack of willingness to discuss the fallout from Scottish independence in relation to the rest of the UK. Why should it fall to the First Minister of Scotland to make provisions for Cornwall, Wales and Northern Ireland following the break-up of the UK? Surely it's up to the citizens and politicians of those regions to prepare for such an event.

David Cameron could convene a "Conference of the Isles" by inviting participants from all of the regions, including Scotland and the Republic of Ireland, for a discussion on the future should Scottish independence become a reality.

Cian Carlin

London N4

A breakaway Scotland would have a huge job setting itself up as a state. As the Government's new publication "Scotland analysis: Devolution and the implications of Scottish independence" points out, it would have to apply to join the United Nations. The UN Charter has no provision for automatic succession to membership.

A breakaway Scotland would also have to apply to join the EU. There would have to be negotiations before Scotland could join and any agreement would have to gain the consent of all existing EU members, including Spain, whose government fiercely opposes any would-be Catalan or Basque breakaway. Scotland would also have to join the euro, or negotiate an opt-out.

As the Government observes, "The Scottish Government has suggested that an independent Scotland would retain use of sterling. As leading economists have pointed out, if representatives of an independent Scottish state wanted to do this without launching a new currency pegged to the pound, they could unilaterally adopt the pound or seek an agreement with the continuing UK for a formal currency union."

Both are problematical, as it adds: "Under the first option, an independent Scottish state would not be able to have a say in its monetary policy" and "as recent experience of the euro area has shown, it is extremely challenging to combine a formal currency union with full fiscal independence".

Will Podmore

London E12

It is reported that the Welsh Assembly might be given powers to vary rates of income tax to help boost the country's economy (25 February).

Few Welsh workers earn more than £34,000 a year, and average house prices are much lower than in England. High-skilled, highly paid jobs have been replaced by work in call centres or online warehouses.

Wales does not need wealthy incomers who drive up property prices. We need well-paid jobs to enable people to afford homes of their own.

Mike Stroud

Sketty, Swansea

Pistorius and the reality of living with fear

I left Johannesburg in 1962. We had several heart-stopping break-ins. Then, mostly, you might get beaten up – but not killed, as it seems to be these days. However, a neighbour was killed in his garden when we were there.

A friend of ours awoke and saw a figure in the dark. He shot. As he was half-awake, his shot went into the wall; and the person he had shot at was his wife. After that, we got rid of the gun we had kept in the bedside cupboard. Bearing all this in mind, I would give Oscar Pistorius the benefit of doubt.

Lorna Roberts

London N2

Contrary to Vivienne Pollock's belief (Letter, 25 February), the situation she outlines regarding her trip to the bathroom one night three years ago bears no similarity to the death of Reeva Steenkamp.

Oscar Pistorius was not half-asleep, as, according to his reported testimony, he had gone on to his balcony to find a fan.

It also seems he had to pass the bed in order to reach the bathroom complex. On the way he presumably had to pause long enough to find a loaded gun. Could he not also have paused to ascertain that the person he thought was sleeping in the bed was actually doing so? I would have thought that this would have automatically happened before the gun was even thought about.

Janice Jowett

Ormskirk, Lancashire

Stop drugging the elderly

It has been reported that elderly people in care homes, as opposed to those in the community, are 20 times more likely to be on antipsychotic drugs.

In many nursing homes the elderly often appear submissive, vacant, with a lifelessness about them – often brought on by the use of antipsychotic drugs.

This abuse is the result of the psychiatric profession manoeuvring itself into an authoritative position over aged care. It has perpetuated the tragic but lucrative hoax that aging is a mental "disorder", a for-profit "disease" for which it has no cure, and which requires extensive and expensive psychiatric drugs.

Rather than being cherished and respected, too often our senior citizens suffer the extreme indignity of having their power of mind nullified by drugs.

Brian Daniels

Citizens Commission on Human Rights (UK)

East Grinstead

What about our sportswomen?

Philip Hensher's column on Oscar Pistorius ("Look up to anyone – just not sportsmen", 16 February) touched a nerve. His argument that the downfall of Pistorius, alongside the litany of failures of other sportsmen (Lance Armstrong, Tiger Woods, John Terry) should spell the end for holding up sportsmen as role models contains a crucial omission: women.

Sportswomen, either explicitly or implicitly, are excluded from Hensher's discussion of sportsmen as role models. I'm not into sport. Yet I can reel off a list of excellent sportswomen: Jessica Ennis, Kelly Holmes, Rebecca Adlington, Christine Ohuruogu, Tanni Grey-Thompson, Nicola Adams, Paula Radcliffe, Venus and Serena Williams, Ellie Simmonds, Gemma Gibbons... And the only thing I can think of that could be considered to be the "tragic fall" of any of these sporting heroines? Radcliffe squatting down to relieve herself mid-marathon. Seriously.

So when Hensher declares that you should "Look up to anyone – just not sportsmen" (suggesting, instead, bankers for role models?), he writes women out of history. Clearly Olympic golds aren't enough to make a sportswoman and a role model – or at least not in the mainstream, male-dominated press. This serves not only to discredit the achievements of sportswomen, but it also tramples roughshod over those who do hold them up as role models.

The headline should have read: "Look up to anyone – just not sportsmen. Sportswomen are ace role models."

Alice Stott

London School of Economics Students' Union Women's Officer

London E2

Danica Patrick, a racing car driver, is described by at least one commentator as "the most important female athlete on the planet" (23 February). Athlete? I think not. Notwithstanding the Greek root of the word, with its association of striving for a prize, the modern use of "athlete" implies much muscular effort and hard working of limbs, not sitting in a chair at a control panel. A better word might be operator, technician or driver. Yes, that's it. She is a driver.

Colin Hayward

Fareham

Still worshipping at the urinal

I'm surprised Adrian Hamilton (Arts, 25 February) doesn't know that Duchamp's urinal continues to be the touchstone of our edgy, subversive contemporary art.

Never mind that it was followed by his "retirement" from art. In other words, it was the end. Art was finished. Au contraire! His contemporary legions of followers are happy to live in 1917, leaning nonchalantly on their own urinals, with their canapés, in galleries around the world every day.

Little did Duchamp know that his end was only the beginning of our brave new academicism where no work can be taken seriously if it is merely painting or sculpture.

Now, any self-respecting contemporary gallery and its public must be abused. "What boundaries are you breaking?" they cry. "What hierarchies are you subverting?" "Aren't you going to give us a good seeing to for being capitalist lackeys?" and "Haven't you got anything a bit like a urinal, darling?"

Martin Murray

London SW2

One rule for all

The way to stop excessive pay rises (and scurrilous bonuses) in the boardroom would be to force those companies making 20-40 per cent increases to do the same for the workforce. If the bosses' success warrants a 40 per cent pay rise, so does that of the workforce. If the workforce only deserves 1-2 per cent, the same should apply to the board.

Dave Morgan

Beddington, Surrey

It's the tax, stupid

I did not go to Eton. I am merely a former local government officer who had to make do with a grammar school education. But I can tell that bloke who is Chancellor of the Exchequer that the way to reduce the country's debt and at the same time increase productivity is to tax the rich to limit the amount they can stash away abroad, and reduce the burden on the poor who will spend the little extra they get and boost productivity.

Brian Crews

Beckenham, Kent

Dead meat

Nick Clegg described the Eastleigh by-election as a "two-horse race" between the Lib Dems and the Tories. As the horse meat scandal deepens, he couldn't have found a more apt metaphor. Both parties will be minced meat come the next election.

Sasha Simic

London N16