Panel study

A panel study is a longitudinal study design where a cross-sectional sample of units is selected and surveyed at usually regular intervals. The observation units may be individuals, households, firms or other organisations, or even countries.

Household panel surveys are an important sub-type of panel study. These draw representative samples of households and survey them, following all individuals through time on a usually annual basis. Examples include the US Panel Study on Income Dynamics (since 1968), the German Socio-economic Panel Study (since 1984), the British Household Panel Survey (since 1991), the Household, Income and Labour Dynamics in Australia Survey (since 2001) and the European Community Household Panel (1994-2001).

The advantage of panel data is the longitudinal observation of the individual through time, and the collection of data at regular intervals, so recall error is reduced. However, panel surveys are expensive to conduct, are sensitive to attrition and take a long time to generate useful data.

The collection of time-series data for multiple countries can also be considered a form of panel study, and shares the main structure of panel survey data, where for each variable there is an observation per unit per timepoint. An example of this type of panel is the Luxembourg Income Study (LIS).