Correlations between consecutive observations (grouped by individual)

[PaigeMiller]

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@Wafflecakes wrote:

How would I do a correlation between consecutive years (grouped by id)? e.g. Correlation between measure1 in 2001 with measure1 in 2000, measure1 in 2002 with measure1 in 2001, etc.

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Normally, one does not speak of correlation between row 1 and row 2 of a data set. The correlation is not defined in this manner, and has no particular meaning. (Or, it is a degenerate case where the correlation between row 1 and row 2 is always equal to ±1)

One can speak of a correlation of ALL the rows for a given variable where ID = 1, and a correlation between all the rows where ID = 2, but this is different than your row-by-row correlation.

So, could you please clarify?