To find some reliable numbers, I looked at the statistics from UK and Ireland. Both of them maintain detailed records of how many Eastern Europeans arrived to work there. There are 25,956 Latvians who have registered with Irish authorities from May 2004 (the date when Latvia joined EU) and July 2007 (the most recent month for which they have data). UK reports 34,460 Latvian workers arriving there up to end of June 2007. Those are substantial numbers of people, although they are less than the wildest claims by media.
Also, looking for a better life in Ireland or UK is far from being specific to Latvians. There are substantial numbers of Poles, Slovaks, Lithuanians there, as well. Latvia, however, has the second highest emigration rate in EU8. (Lithuania is the only country with a higher emigration rate.) By breaking down the numbers by year, we can see that the emigration is rapidly decreasing and the number of people who left Latvia in 2007 only a half of what it was in 2005.
Irish and UK data have one thing missing in them. Both countries register people who arrive there. They don't record whether those people are still there or not. So, we know that there were 60,000 Latvians who worked in UK or Ireland at some point... but some of them may be back in Latvia now.
Now, there is a new set of data. In April 2006, Ireland had a census, recording everyone who was in the country on the census day. Here are the numbers:
55,076 PolesThe number of Estonians and Slovaks was too small to make the press release. Comparing those numbers with the registration statistics, we see that 62% of Latvians who registered with Irish authorities were still there on the Census Day. For other countries, the similar percentage ranged from 38% (Slovakia) to 64% (Czech Republic).
Quite a few of those people who move to Ireland, stay there. But quite a few people also return to Latvia (or Poland and Estonia). Sometimes, the life in Ireland only looks better from a distance.
The data is from the last year. If the same trend is still true today, the number of Latvians who have moved to UK or Ireland and are still there, should be in the 30,000-40,000 range. Substantial but far from 100,000 numbers that get thrown around in the news.