I celebrated New Year in Sofia, watching with interest the debate about immigration from Bulgaria at the end of transition controls while in the country myself.
Like Bucharest, Sofia is notably poorer than other European capitals, yet new shopping centres were thriving, and doubtless these economies will continue to grow.
In the meantime, however, there have been concerns that, now that the seven-year transitional controls have been lifted, a wave of Romanian and Bulgarian migrants will come to Britain to work.
It's not clear what numbers may be involved and there are no official estimates, but some of the claims have been exaggerated.
Still, it's true that the free movement of people is a fundamental principle of the Single Market.
Many EU nationals work in West Sussex, including in this constituency. Some local employers doubt that workers would otherwise be available or willing to do some of the factory or horticultural jobs involved.
Indeed, Britain's economic growth over recent years has paradoxically been assisted by labour from other countries while we maintained a jobless section of our population.
That's one of the reasons why welfare reform, making sure that work pays, is so important.
Of course, it is possible to argue that we should go further and end the free movement of labour altogether, which would mean withdrawing from the EU.
And people would have the opportunity to vote for that in the referendum on EU membership, which a Conservative Government would introduce by 2017.
We will need an informed debate about the implications for business of not being in that market.
A less drastic alternative would be to slow full access between EU country labour markets until we can be sure it will not cause vast migrations.
That would require major renegotiation and is what the Prime Minister has proposed - significantly, with the support of other EU countries, such as Germany.
These aren't simply questions of economics. The social impacts of migration also matter, including on community cohesion and public services.
Public concerns must be recognised. The Government has announced new measures to restrict the claiming of benefits and access to free healthcare by foreign nationals.
It's also important to note that immigration from non-EU countries can and has been reduced sharply. Net migration to the UK is down by a third since 2010.
Sensible controls on immigration will rebuild public confidence.