Table 2 CD test and Slope heterogeneity test results
| Â | CD test | p-value |
|---|---|---|
CD Test results | ||
 lnGDP | 22.86*** | 0.000 |
 lnLF | 19.77*** | 0.000 |
 lnREC | 17.10*** | 0.000 |
 NREC | 22.24*** | 0.000 |
 lnEE | 20.31*** | 0.000 |
 lnEC | 19.80*** | 0.000 |
| Â | Delta | p-value |
|---|---|---|
Slope heterogeneity test results | ||
| Â | 10.860*** | 0.000 |
 adj | 12.771*** | 0.000 |