Nonlinear Cointegration and Asymmetric Adjustment in Purchasing Power Parity of the USA, Germany, and Pakistan

Table 1

Null and alternative hypotheses for monthly unit root test.

Test of unit root at different frequencies	Null and alternative hypotheses
Zero frequency unit root
Biannual frequency unit root
Seasonal frequency unit root	at least one of them is not equal to zero; where j = C, D, E, F, G and i = 3, 4, 5, ...., 12