Scottish election: Adding up the party promises
You've heard the saying about numbers, "there are lies, damned lies and statistics".
Everyone should be wary of numbers and statistics in politics.
It doesn't really matter if you promise to give your friend some money next week then realise later on that you can't afford it.
If a politician makes the same pledge to spend money on something before the election we expect them to stick by that decision afterwards.
But do the main Scottish parties' pre-election manifesto finances add up?
The centre has released a paper analysing the funding promises in the manifestos of the main Scottish political parties.
The CPPR claims that future funding "issues have been addressed by some of the parties".
But it adds: "In most, they have been avoided, or only addressed in a token manner. In place of the difficult decisions, decisions of unproven worth have been relied on."
Where some parties have pledged to spend money, the CPPR has struggled to identify exactly where they will find the money to pay for it either through savings or cuts.
Senior Research Economist Gemma Tetlow, from the London-based Institute for Fiscal Studies (IFS), said: "Poll ratings can go down quickly if you're speaking out about what you'll cut before an election when no other party is speaking out too.
"We definitely saw in the UK elections that politicians didn't speak in real detail about financial issues before the election took place.
"What we ended up seeing was parties focusing on what they would keep with the implication that cuts would come from what they didn't focus on."
It's no fantasy that the government elected will have to make some "difficult decisions" over the next four years.
The CPPR report said that currently: "Voters are entitled to be highly sceptical as to whether what they are being offered in the manifestos is actually what will happen, rather than a pale imitation of the difficult choices that await, post-election."
Perhaps this scepticism is one of the reasons why Scottish election voting levels have struggled to get much above 50% since devolution.
Is it naive to ask parties before it gets to election day exactly what will stay and what will go if you vote for them?
It's less painful to rip off a plaster and confront the ugly mess beneath rather than peel it off slowly, wondering what awful wound awaits.