We (i) formalize long-run neutrality (LRN) and long-run superneutralit
y (LRSN) in the context of a bivariate ARIMA model, (ii) show how the
restrictions implied by LRN and LRSN depend on the orders of integrati
on of the variables, (iii) apply our analysis to previous work, showin
g how that work is related to LRN and LRSN, and (iv) provide some new
evidence on LRN and LRSN.