Series unit-root tests
| Levels with constant and trend | Test statistics | ||
|---|---|---|---|
| Series | ADF | PP | KPSS |
| Quantity of manufactured cigarettes (MC) | −7.94*** | −7.95*** | 0.09 |
| Quantity of RYO loose tobacco | −8.32*** | −8.44*** | 0.13* |
| Real price index for MC | −3.51** | −3.24* | 0.11 |
| Real price index for RYO loose tobacco | −2.17 | −4.24** | 0.19** |
| Average weekly income | −2.45 | −7.02*** | 0.18** |
Notes: KPSS H0: no unit root; ADF and PP H0: unit root.
*, ** and *** indicate significance at 10%, 5% and 1%, respectively.
ADF, Augmented Dickey–Fuller; KPSS, Kwiatkowski, Phillips, Schmidt and Shin; PP, Phillips–Perron; RYO, Roll-Your-Own.