This section will discuss some of the basic kinds of research question that require linked macro and micro data. Since different kinds of question regard different kinds of variation between macro units, the next subsection will discuss different analyses that can be used identify these different kinds of between macro unit variation, before the macro data has even been linked to the micro data. It is worthwhile spending time considering the analyses in this section, since it is a good idea to understand some of the main characteristics of the variation between macro units in the micro data before you try to use macro level variables to explain that variation. This may also help alert you to the presence of any unusual macro units or any problems with your data.