Table 5.
Panel unit root test
| Variables | IPS | ADF-Fisher | CIPS | CADF |
|---|---|---|---|---|
| Covid-19 cases | −9.318*** | 135.168*** | −1.825 (-2.812)*** | −5.279*** (−1.501)* |
| Covid-19 deaths | −14.406*** | 230.317*** | −1.645** (−3.641)*** | −1.501* (−6.504)*** |
| Air pressure | −22.334*** | 446.182*** | −4.263*** (−4.379)*** | −4.347*** (−4.519)*** |
| Humidity | −23.429*** | 474.630*** | −5.456*** (−5.106)*** | −5.462*** (−5.167)*** |
| PM2.5 | −24.011*** | 489.745*** | −5.886*** (−5.289)*** | −6.054*** (−6.045)*** |
| Temperature | −22.269*** | 429.840*** | −4.433*** (−4.606)*** | −4.365*** (−4.595)*** |
| Wind speed | −22.981*** | 461.491*** | −5.126*** (−5.434)*** | −5.122*** (−4.951)*** |
Source: authors’ computation
*, **, and *** denote statistical significance at 10%, 5%, and 1% levels, respectively
Parentheses denote ∆CIPS or ∆CADF, i.e., at first-level difference