Spatial market integration of rice in Bangladesh in the presence of transaction cost

Agricultural and Food Economics

Table 2 Unit root test results

Prices series		Deterministic terms in test equations		First differences (τ_pw)	Order of integration, I(d)
Prices series		τ_c	τ_c,t	First differences (τ_pw)	Order of integration, I(d)
Dhaka	ADF	− 0.633	− 2.971	− 10.687***	I(1)
Dhaka	PP	− 0.866	− 3.360	− 17.200***	I(1)
Mymensingh	ADF	− 0.626	− 3.078	− 11.744***	I(1)
Mymensingh	PP	− 0.646	− 3.150	− 16.400***	I(1)
Rajshahi	ADF	− 0.555	− 2.672	− 9.078***	I(1)
Rajshahi	PP	− 0.633	− 2.810	− 12.700***	I(1)
Khulna	ADF	− 0.825	− 3.324	− 11.022***	I(1)
Khulna	PP	− 0.996	− 3.380	− 16.700***	I(1)
Chattogram	ADF	− 1.136	− 3.276	− 12.365***	I(1)
Chattogram	PP	− 0.942	− 3.160	− 13.700***	I(1)

***Indicates that unit root in the first differences is rejected at 1% significant level; \(\tau_{c}\), \(\tau_{c,t}\), and \(\tau_{pw}\) indicates tau-statistics of random walk with drift \(\left( {\tau_{c} } \right)\), random walk with drift and slope \(\left( {\tau_{c,t} } \right)\) and pure random walk \(\left( {\tau_{pw} } \right)\) models, respectively; critical values are − 3.44 (1%) and − 2.87 (5%) with constant only model; − 3.98 (1%) and − 3.42 (5%) for a model with constant and trend; − 2.58 (1%) and − 1.95 (5%) for pure random walk model, respectively (Mackinnon 1996)