From: Effects of crude oil prices on copper and maize prices
 | With constant | With constant and trend | Without constant and trend |
---|---|---|---|
t-statistic (p value) | t-statistic (p value) | t-statistic (p value) | |
LOG_MAIZE | − 1.9124 (0.3265) | − 2.9578 (0.1455) | 0.4227 (0.8044) |
LOG_COPPER | − 1.1693 (0.689) | − 2.4639 (0.3461) | 0.9403 (0.9079) |
LOG_CRUDE_OIL | − 1.6902 (0.4356) | − 2.9765 (0.1400) | 0.0494 (0.6981) |
d(LOG_MAIZE) | − 16.4611*** (0.000) | − 16.4612*** (0.000) | − 16.4635*** (0.000) |
d(LOG_COPPER) | − 6.0474*** (0.000) | − 6.0452*** (0.000) | − 5.9588*** (0.000) |
d(LOG_CRUDE_OIL) | − 14.2595*** (0.000) | − 14.2537*** (0.000) | − 14.2684*** (0.000) |
Result | I(1) | I(1) | 1(1) |