which year dummies are required for regression analysis for regression is year a factor variable is age group factor a covariate which factor is used to test for a linear dependence? pphpy r linear dependence what is the problem with years in regression which factor can be an independent variable what is the problem with a regression with the year dummies what is the relationship between age group and time trend is dummies a linear variable how to run a linear regression with year and year dummies? is an age group factor covariate how to do a regression in r with year and dummies how to create a linear regression does agegroup affect regression how can i find out if a regression has a linear dependence which regression method uses year dummies? which r regression problem would include years as independent variables r how to solve a linear dependency r how to check whether age group is linear