Notes: Standard errors in parenthesis. * represents significant at 5%; ∇ = (1 - B) and ∇12 = (1 - B12): regular and seasonal differences; B: lag operator; ΔPTCi (i = TC, JTC): rates of growth of deflated price for TC tickets; MRL: Metro route length; LBQ: Ljung-Box Q statistics; = residual standard error.