what is the unit root of log x x y t how to determine which regression model uses two different methods which difference is i(2) in regression? which i(2) process has the second difference in the y_t? how do i calculate the second difference if the first difference is i(1)? how to determine whether unit root is stationary how to find the unit of regression of log x_2t what is the difference between i(1) and i(2) regression which statement best describes the difference between the i(1) and the i(2) process? which % of y_t in delta is stationary what is the difference between y-t and x-t how to calculate t in regression what is the second difference of x what is the first difference for the first difference what is the relationship between log x and log y what is second difference in beta when you have both i(1) and i(2) processes, you can estimate what is the relationship between y_t and x_t in regression what are the second differences of i(1) and i(2) what is the second difference of an i(1) series