I know that there are similar questions but I hope this is not a duplicate, unfortunately I can't tell due to my limited knowledge about statistics..
I have annual data covering a period of 100 years (one predictor and one dependent variable). I'd like to investigate the relationship for the years 1-50 and for the years 51-100, so I fit a linear regression for each period. However, I'd also like to know if there is a significant difference between those two models (i.e. determine whether it makes sense to split the dataset). What test would I use for that?