Robuta

https://www.stata.com/statalist/archive/2010-03/msg00038.html st: Panel LM Unit Root Test with Heterogenous Structural Breaks unit root test panel heterogenous structural breaks https://www.jamelsaadaoui.com/fourier-df-unit-root-test-for-rd-intensity-of-g7-countries/ Fourier DF unit root test for R&D intensity of G7 countries – EconMacro unit root test fourier intensity countries