These tests showed that the Rmi t and Gi t variables did not have to be treated as endogenous variables and that the use of the second lags of the variables and the additional instruments required by the system GMM are valid. The results of these tests are shown in tables 2,3 and 4. None of the estimates rejects the null hypothesis, so the residuals exhibit a first-order correlation. In order to prevent the estimates from being biased, it is necessary to mitigate their presence.