Britain's oldest economic think tank believes that the economy could shrink by more this year than it did in 1931.
That's not good. But it's not as bad as you might think.
We've all heard so much about the Great Depression in the US, we forget that for Britain, the Great Depression wasn't that Great.
In the worst year of the Depression, our national income shrank by 4.6%. That's the figure that the National Institute of Economic and Social Research (NIESR) has in mind when it makes the comparison with 2009.
In its latest Economic Review, it forecasts a decline in GDP this year of 4.3%, but, as the authors demonstrate, the pace of the downturn to date has been on a par with 1930-1931.
The Chancellor, Alistair Darling, will not relish the historical comparison. No-one in the Labour party likes to be linked to anything that happened in 1931.
For those that don't know, that was when the Labour Prime Minister, Ramsay MacDonald, was forced out of office by the economic crisis, but then agreed to be part of a national government with Labour's enemies. For Labour, it's an act of party betrayal that has been handed down the generations.
Still, economically speaking, 1931 was not half as bad for the UK as it was for other parts of the world - notably the US, which shrank by more than 10% that year, and by around 30% between 1929 and 1933.
Where the UK is concerned, the year you really don't want to replicate is 1921, when the economy shrank by nearly 10%.
Thankfully the NIESR doesn't think that we're approaching that territory right now. Although you might imagine so, given the carnage afflicting the public finances.
Like many others, the institute thinks that the chancellor's being optimistic about the strength of the recovery from 2010.
To remind you, Mr Darling is forecasting growth of 3.5% from 2011 onwards (though he's using a more conservative forecast of 3.25% in his predictions for the public finances).
As I noted on Budget day, that's not unheard of. We often have rapid growth of that kind after a recession, especially a deep one.
But, as I also remarked, it's not what economies have tended to see after major financial crises.
Nor, as the authors of this report point out, is it necessarily what you would expect to see in a year when the government is expecting to subtract 0.7 percentage points from overall growth in GDP.
For the economy to grow 3.5% against that backdrop, the rest of the economy would have to grow by 4.25%.
Again, that has happened before. But not since 1988, which was itself the peak of an unsustainable boom.
Many economists I talk to are starting to sound much more optimistic about the next year. After the kinds of declines we've seen over the past six months, there's a sense that there is only one way the numbers can go.
But even if we were to see growth on the order of 1% next year, I haven't found many who expect several years of rapid growth from 2011.
Maybe the Budget forecast will be right, and the Treasury will get the last laugh. Where the growth forecasts are concerned, it's happened quite a few times in the last few years.
But the same cannot be said of the Treasury's borrowing predictions. If the NIESR is even slightly right on those, net debt is going to approach 100% of GDP by 2015-16, and things could be a lot stickier than the markets now expect.