Practically all construction statistics are poor by comparison to the data in most other industries. It is not a fault of the statisticians or researchers. They have an unenviable job as the construction industry is, relatively speaking, very tricky to measure.

So the best way to make sense of what is really going on it to look at a wide range of information and see what matches and what clashes and glean information wherever you can.

Valuable insight into the state of construction – or for that matter the economy generally – doesn’t have to come from the collected Government statistics or well-managed industry trade surveys.

I, by chance, monitor activity at a job centre near me, because if you accidentally switch the 6 and 9 in my office phone number you end up speaking to the job centre and visa versa. So naturally a proportion of job centre calls come to me as wrong numbers.

Interestingly I have noticed a surge in activity recently.

Many people use the London taxi test. If your average waiting time falls and the number of drivers being polite rises, it is a pretty good sign of an economic slowdown.

So when I read the story recently about Tesco sales of specialist Polish goods on the rise again after a sharp fall at the start of the year my eyebrows were raised.

According to the story I read and the press release that prompted it, the sale of Polish goods was going great guns until the end of last year.

Then in December 2008 it seems they fell by 23% compared with the previous year. This is thought to have coincided with a flight back home of Poles struggling to find work as the UK economy rapidly contracted.

This flight of migrant workers has helped to take some of the sting out of the unemployment figures and might be one reason the figures have risen slower than many might have expected given the severity of the economic downturn.

National statistics show that UK nationals have in one sense benefited from the high level of migrant labour working in the UK, as the fall in overseas workers within the ranks of the employed has been far sharper than the drop in employment among UK nationals.

But unemployment in Poland is on the rise. Up about 300,000 on a year ago according to the Eurostat figures I checked. And male unemployment appears to be rising faster than female unemployment – up 200,000.

The Polish press, says Tesco, is reporting that Poles are once again being increasingly tempted to try their luck in the UK. The result for Tesco is would appear is a 15% bounce in sales of specialist Polish goods.

For construction workers in the UK the result may not be as pleasing as it is for Tesco. If the increase in Poles in the UK is in part down to Polish construction workers being less inclined to return home and if more are deciding to return to the UK from Poland, it might just become a tad harder to find a job.

But before despair overwhelms, there is good news on the migration front in the data. Closer analysis of claimant count data shows that ever more unemployed construction tradesfolk and professionals are leaving the UK dole queue for foreign shores, so taking themselves out of the UK jobs market.

The data show that the proportion of tradesfolk signing off to head abroad over the six months to October this year was about three times what it was, on average, in the two years before the credit crunch.

The figures, which probably are more indicative than reliable, show that in the summer more than 2,000 construction tradesfolk were signing off dole each month to head abroad.

And the rise in the proportion of professional and technical staff was far sharper.

The data are insufficiently granular to be certain, but it looks that around 1,000 construction-related professionals and technical people were signing off a month and heading abroad this summer. This compares with an average of about 200 a month over the two years before the credit crunch.

But then again, how many will be returning from Dubai? And so the picture gets muddled.

I’m just left wondering how well Tesco measures its sales of Marmite, Tetley tea bags and bacon rashers overseas and what that might tell us about the UK construction diaspora.