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Table 2 Unit root test results

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

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