# Creating an AbstractDataFrame subtype

**URL:** <https://discourse.julialang.org/t/creating-an-abstractdataframe-subtype/36451>\
**Category:** General Usage\
**Tags:** question\
**Created:** [March 24, 2020, 2:37pm UTC](https://discourse.julialang.org/t/creating-an-abstractdataframe-subtype/36451 "2020-03-24T14:37:22Z")\
**Posts on this page:** 2\
**Page:** 2

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**Author:** ![oxinabox](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/oxinabox/32/206603_2.png) [@oxinabox](https://discourse.julialang.org/u/oxinabox)\
**Post date:** [July 27, 2021, 8:55am UTC](https://discourse.julialang.org/t/creating-an-abstractdataframe-subtype/36451/21 "2021-07-27T08:55:03Z")

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As I understand it,  
Panel Data is already represented as a `GroupedDataFrame` where you `groupby` the unit/location/etc, and you have a time column.

We should think about adding lags overloads for that in packages that do lags.

For years I was confused by panel data, until I realized that.  
I think encouraging thinking of it as 1 particular case of `groupby`/`GroupedDataFrame` is good.  
Econometricians have played us for fools.

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**Author:** ![Tamas\_Papp](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/tamas_papp/32/25949_2.png) [@Tamas\_Papp](https://discourse.julialang.org/u/Tamas_Papp)\
**Post date:** [July 27, 2021, 9:12am UTC](https://discourse.julialang.org/t/creating-an-abstractdataframe-subtype/36451/22 "2021-07-27T09:12:53Z")

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I also support innovation, I am just not convinced that it requires a subtype. I may be mistaken, but this looks like something that can be handled with the existing API (possibly calling `groupby`, but hiding that from the user when it makes sense).

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