For UK data I would look at fig.4 and table 4 in this document for projections of the aging poulation:
http://www.statistics.gov.uk/downloads/theme_population/PT118_V1.pdf

On your point 1, while I agree that there does appear to be a contradiction between the policies you mention there are two ways of looking at it.

It could be argued that this is all about politicians current favourite word ‘choice’. If you stop contraception and abortion you are restricting choice by removing the option of not having children. If you introduce support for people with children then you are merely creating an incentive but still leaving the individual with a choice.

A slightly more sinister argument is that this is all about social engineering. If you stop free contraception and abortion then the people most affected are those that cannot afford to pay for it themselves - end result is lots more children in the C1DE classes. If you offer tax breaks and contributions towards childcare as an incentive then the people most incentivised are those earning enough to benefit from the tax breaks or pay the rest of the childcare fees - end result is lots more children in the ABC1 classes. In blunt socio-biological terms, do you want more shelf fillers for Tesco or more scientists for Glaxo?

On your point 2 I agree. I haven’t seen any data to prove that these policies are leading to an increased birth rate. All I am doing is speculating.

On your point 3, these people are called the ‘free-riders’ i.e. people who benefit from a policy who benefit from a system without putting in any extra effort - they have already decided to have the children. These people could also be viewed as marketing agents for the policy. Anyone who works in marketing will tell you that the best way to get people to buy your product is to get all of their friends and family to tell them how great it is. What better advert could their be for the rewards for having children than being told by everyone around you how much extra cash/help they are getting? It may not make you think ‘lets go out and procreate’ but if you were already thinking about it but worrying about whether you could manage it could make all the difference.

Of course you could ignore everything I’ve said and believe what the Government says. Poverty is a hard habit to break. If you can give children a better start in life then they are likely to be better off in adulthood. Its a theory based on good data and I’m not saying its not true. I just like speculating around the edges.

I really don’t think this is the case. The government hasn’t ever used this rationalisation, and people only ever bring it up as a fall back position when it’s pointed out that people don’t deserve being given other peoples money for having kids. The "we need more children" lines is just hyperbole, plenty of perfectly successful nations have had a much worse situation than us for a while. UK birth rates have increased spontaneously recently, before the government did anything to influence them. The measures are a solution looking for a problem.

It’s also worth bearing in mind. (1) This aim on the part of the government is totally inconsistant with it - at the same time - spending a lot of effort getting people not to have children (i.e. teenage mothers, abortion provision). If you really wanted to increase the birth rate, this could be done at the stoke of a pen by ending state funding for contraception and abortion. (2) There’s no empirical evidence at all that the policy encourages more people to have children. No one is even claiming it does. (3) Logically, how on earth does giving benefits to people who have had children in the past - before the system started - encourage people to have children? They’ve have already made the decision to have children without the bribe. You’re giving away public money for no benefit. If you were to try and bribe people to have children, it’d only make sense (and would be much cheaper) to do it by bribing people who have children starting from now.

If people aren’t procreating then we will have to get our future workforce from another source. Increased immigration is the obvious answer but that means taking on the racist bigots in the tabloid media and the general public - something neither Labour or the Tories seem keen to do.

One way or another, in 30 years time there had better be enough people working and paying taxes in this country or we are going to have a lot of pensioners starving in the streets.

This whole move strikes me as being as being totally unjust. And is taking place virtually unopposed. It entails a huge expansion in the Welfare State, which is being pushed away from its old Beverage roots into offering targeted bribes at particular sections of voters. I have no problem with the welfare state targeting the demons of povery, disease, ignorance, idleness, etc. But I can’t see why it should attempt to relieve people of the burden of looking after and paying for their own children. It escapes me why this is happening at the same time that the Government is shrinking other areas of welfare provision.

Both main parties are explicitly favouring an increasing redistribution of wealth from people who do not have children to people who do. The system that is being set up is offering expensive perks to people who are not by any means poor or in need of Government aid. It’s also spreading into other sectors of life, including business. In the past men were paid more at work than women on the basis that they had a family to support. This was - thankfully - replaced by the doctrine of equal pay for equal work. I can’t see why this is now being demolished and replaced with a systen where people with children are, in effect, being paid more for doing less work. I don’t see how any of this can be justified as something the state should be doing. I also can’t see anyone trying to justify it, it’s basically just a electorally motivated bribe.

I’m going to sign off now, before this degenerates (further?) into a rant. But I’d be very interested in hearing anyone elses opinions on this aspect of Government policy that is, more-or-less, completely uncommented on.