Finally, we may wish to look at interactions between individual and aggregate explanatory variables. In this example we can look at the interaction between a person's age and the amount of long term unemployment in the country in which they live: - this enables us to ask the question 'is there any evidence that age relates to the change of voting differently in countries with high long-term unemployment compared to countries with low long-term unemployment?'. We could also look at other kinds of relationship with this model framework e.g. include an individual level explanatory variable indicating whether or not someone is unemployed and interact this with long term unemployment in the model to assess whether unemployed people in countries with high long-term unemployment are more or less likely to vote than in coutries with unemployed people in low long-term unemployment.