I have a dataset which contains 18 quarterly datasets from the Labour Force Survey which have been merged together for me to conduct data analysis. There are around 25000 observations and 21 variables. I wish to run panel regression as the data is from a combination of countries in the UK so this would be most accurate. However, when I try using the command 'xtset panelvar timevar' the error 451: repeated time values within panel is returned. I have tried using different panelvar however the same result is always returned. I have gathered that the reason for this may be that there are more than one panelvar timevar combinations in my dataset however I cannot figure out how to solve this problem.