Reality check: who benefits from frozen council tax?
It's a vote winner, for sure. Do you want to have your tax frozen at 2007 levels? Of course you do.
But at what price? It's a simple enough mechanism that has persuaded councils to freeze tax, as my colleague Jamie McIvor has explained.
They get offered a total of £70m each year, shared between them, on condition they don't increase council tax. If they refuse it, they lose out twice - first, their share of that money, and second, they have to charge more from local taxpayers.
But what is this costing central government? It's not simply £70m each year, because the costs of delivering services keep going up.
The second year of a freeze requires £140m, the third year £210m, and we're now in the fourth year of the freeze, so St Andrew's House has to hand over £280m to sustain services at 2007 levels.
All four main parties are committed to continuing the freeze for 2012-13, so that will require £350m that year, with Labour adding £10m extra to acknowledge extra cost pressures.
LibDems say they'll take the poorest pensioners out of council tax - those under £10,000 income per year, while Conservatives offer a £200 discount to all pensioner households.
The SNP is committed to going further into the next parliament, and continuing the freeze until 2015-16.
If that still means a £70m extra grant each year, that will come to £560m.
Passing the half billion pound mark is a reminder that this is becoming a sizeable chunk of Holyrood's budget - money that obviously won't be available for other priorities.
What we've heard today from the Convention of Scottish Local Authorities (Cosla) is an additional £70m each year isn't enough. Consumer inflation is now running at 4%, whereas the implied inflation rate within the £70m grant is about 2.75%.
That helps explain why Cosla say they would require more than £100m each year to keep up with their costs.
Behind it is an anguished cry about the relationship between councils and central government.
Financial autonomy is being eroded with each year of the freeze.
Only 25 years ago, councils looked to central government for roughly half their funding.
They now rely on central government for closer to 85%, and that share keeps growing the longer the freeze is retained.
None of the parties seems to be discussing whether this is healthy for local democracy, and at what point the share of local tax raised has become too small.
Moreover, none of them is willing to go near a revaluation of property.
We're still being taxed on the basis of what a house would be worth 20 years ago.
The top band starts at £212,000 in 1991 prices, for properties now worth somewhere north of three times that amount.
That wouldn't be a problem if all homes increased in value at the same rate, relative to each other.
But they don't, and they haven't.
Some people would lose out from a revaluation.
Welsh experience of it showed significant numbers moving up not one, but two bands, with bills to match.
And Scottish political memories look back with a shudder to 1985, when revaluation caused howls of protest in better-off areas, leading directly to the introduction of the notoriously unpopular community charge, or poll tax, as a means of getting Scottish Tories off the revaluation hook.
However, for all those who would lose out, roughly the same number of householders are being overcharged because the valuation of their home is now too high when compared with others.
It looks like they're being let down by political caution about alienating the losers from such a process.
But let's return to the money, and ask who benefits from the council tax freeze.
There are two ways of looking at it. Scottish government figures, commissioned from officials by SNP ministers, found that a two-year freeze, this financial year and next, will save 1% of household income for the lowest-paid decile (10%) of Scottish households.
You may ask how many of those households pay anything, as poorer households often get council tax benefit.
I haven't been able to find out how council tax benefit is distributed across those deciles.
But put it this way: there are 2.4m households in Scotland liable for council tax, and 560,000 of them get council tax benefit.
It's a fair guess that they are loaded towards the cheaper end of the property range, and Band A for tax.
So for those who get council tax benefit, they don't see any benefit.
For those in the top-earning decile in Scotland, the benefit of the tax freeze will save 0.4% of household income.
So on that basis, it looks progressively fair.
But given this is a cash distribution, who saves most from the freeze? It's not the poorest, but those in the biggest houses who stood to have the largest increases without a freeze.
And as council tax is levied according to a fixed formula across the bands, the savings are substantially skewed towards those in the biggest houses.
If you're in Band A (and don't get benefit), let's assume you are avoiding 2.75% inflationary increases for each year of a five-year freeze.
That means you're still paying £733 on average, and you're saving £106.
If the same inflation rate is applied to a Band H home, you're still paying £2200 per year in council tax, and you're saving £319.
That seems an odd priority for scarce cash in a country biased towards progressive politics.