The Long-Term Impact of Human Capital Investment on GDP: A Panel Cointegrated Regression Analysis

Table 3

Kao panel cointegration test results.

Country group	ADF test stat.	Prob.
Developing countries	−3.860268	0.0001
Developed countries	−4.135364	0.0000

The optimal lag length is determined as 9 for developing countries and 5 for developed countries according to Schwarz information criterion.