To me the term pooled refers to a type of model. For example in a fixed effects model is equivalent to having a distinct model for each level of the factor that determines the panel. Pooled OLS corresponds to pooling the data set over all levels of the factor and estimating a single OLS (assuming that the fixed effects are constant over all levels of the factor. With a multilevel model pooling corresponds to collapsing some levels of the model to get a pooled model. When some individuals leave the panel and others join I would call this an unbalanced panel.
Best Regards John On 12 July 2011 13:26, Allin Cottrell <cottrell(a)wfu.edu> wrote: > On Tue, 12 Jul 2011, Anutechia Asongu wrote: > >> Could someone remind me the difference between pooled and panel >> data. >> Cheers and thanks > > Panel data are data that track measures on a given, fixed set of > "individuals" over time. The phrase "pooled data" is more general: it > implies that the data have both a time-series and a cross-sectional > dimension, but it includes the case where the individuals are not a fixed > set -- e.g. some individuals drop out over time and are replaced by others. > At least that's how I read it. > > Allin Cottrell > _______________________________________________ > Gretl-users mailing list > Gretl-users(a)lists.wfu.edu > http://lists.wfu.edu/mailman/listinfo/gretl-users > -- John C Frain Economics Department Trinity College Dublin Dublin 2 Ireland www.tcd.ie/Economics/staff/frainj/home.html mailto:frainj(a)tcd.ie mailto:frainj(a)gmail.com
