But there are choices to be made about tax revenue and funding of social services and, in all honesty, I think these have and will in the future have much more effect on people's living standards than whether we leave the EU. So take Osbourne's £3,400 per household figure. My family's financial situation is fairly secure and comfortable but we have lost huge sums in recent years due to Tory policies - we will now have to find the full cost of university fees and living expenses for 2 children if we want to give them the opportunities we had (when the DC were born we did not have to plan for this - our costs would have been much smaller.) So that's a loss of £54,000 on fees alone.
Every time house prices increase, that is a cost to us. The government could do something to control house prices but they don't because some people are doing very nicely out of them. When I have to pay for a private health appt because I can't wait 3 months for an appt for a very serious condition, because the gov is dismantling the NHS, that is a cost to my household.
And, as I say, we are fine, in secure jobs. For someone in a less fortunate position, the costs if the last few years of gov policy must be huge.
So the £3,400 needs to be considered against that. Even for my household, if we left the EU and "lost" £3,400, the gov could choose to mitigate that just by reversing the policies of the last few years. For households which have lost a lot more (benefit cuts etc) this would be even more the case.