After the European Union expanded in 2004, many people from Eastern Europe moved to work in Western Europe. This study looked at how this migration affected people's attitudes in Western Europe. The researchers found that when more Eastern European migrants lived in a country, people tended to have more positive views about immigration. This positive relationship was weaker when the economy was struggling. Surprisingly, the study did not find that this migration had a negative impact on trust or support for welfare in Western Europe. This suggests that as more immigrants arrive, Europeans may see the benefits of immigration.