I am trying to use an instrumental variable with a probit regression using ivprobit package. When I run the code, i have this error:
Error in chol.default(mat) :
the leading minor of order 8 is not positive definite
Do you know how to solve this problem? My code is:
ivprobit(Concluiu_Ensino_Superior ~ Idade +
Altura +
Raca_Cor +
Regiao +
Divisao_Rural_Urbano +
Estado_Civil +
Freq_Religiosa |Fec_Adole_18 |Idade +
Altura +
Raca_Cor +
Regiao +
Divisao_Rural_Urbano +
Estado_Civil +
Freq_Religiosa+ Se_teve_Aborto_Espon,PNS_2013_25_a_35_anos)