One of the troubles with contemplating public expenditure is the vast sums of money involved. One can easily understand what a few hundred pounds equates to - perhaps a new piece of furniture. This can be extended to the thousands for extensions to a house or yearly salaries.
Already, by the time we have got to the hundreds of thousands level we have little comprehension of the magnitude involved. We mostly will need to take mortgages for house purchases, and thus such grand payments are broken down into small chunks; converted to a language we understand.
Yet in the public sector we are asked to consider spending millions or billions. The NHS annual budget is 96 billion pounds. This is £1600 for every one of the 60 million UK residents. How can we consider such gargantuan values?
Enter the Crail - the soon to be de facto unit of public investment measurement. One crail is the cost of Crossrail. The cost of the scheme is £15 billion. So one Crail currently is equal to £15 billion.
"Currently?" you might say! Yes, the Crail varies with time as the cost of Crossrail varies, but this is no less or greater a problem than the changing value of money, causing us to continually write "at 2003 prices" or similar after quotes. The Crail is always measured at the current cost of Crossrail.
The symbol for the Crail is Cr, and one can use all the usual SI prefixes. I thus expect conversations such as the following to occur:
[Someone who isn't me]: Can you believe that Beckham's going to LA Galaxy?
[me]: I can believe it and yet still be indifferent to it.
[person 1]: But it's for 8.5 minicrails!
[me]: Yet my indifference remains.
Just for reference, the US National Debt is about 290kCr, the cost of upgrading Trident is about 1.3Cr, Tesco sells 10 mCr of sales through its internet site, the average UK salary is just over 1.54µCr and lunch last week at the noodle bar cost me 1.07nCr. Start using it.