Most education systems in the developed world increase the amount of funding for children as they get older.
But as reported last week, charity Save the Children has called for primary schoolchildren to be funded at the same level as secondary students. It believes that early education has a greater impact on children's life chances.
The charity also argues that a person's future is largely determined by the age of 7, especially among poorer children. If schools are to help these children catch up in literacy and numeracy, the money needs to be spent earlier, it says.
Cuts to public spending during the global recession have not, by and large, affected education budgets, an Organisation for Economic Cooperation and Development survey found in 2010. But it also showed that while most governments had protected education spending, in some countries, such as Hungary, Iceland and the Republic of Ireland, it had been badly hit.
In the US
34 states are providing less funding per student in 2013-14 than in 2007-08
Oklahoma and Alabama have each reduced funding by more than 20 per cent in comparison with 2007-08 levels
North Dakota increased funding by more than 27 per cent between 2007-08 and 2013-14.