Creating a loop for a regression model and store results

[andresrcs]

@Pia

I get the following error message: "Column stock is unknown". Any idea what I am doing differently?

The stock column is created on this step gather(stock, return, starts_with("X")) %>% so I see no evident cause for that error message. Could you provide a REPRoducible EXample (reprex) for that issue?