However, allow me to point out that my data is 5400 stores, each with 5 observations, that's 27K rows. I'm attaching an example of how it looks (first few obs). In each time period, we take note of the type of management that store had. Now I want to model the cost as a response variable, while the type of management as the predictor, over the five time periods. As mentioned above, we have 5400 of these stores hence 27K obs. My understanding is that this is a case of repeated measures.