Jose Cesar Cruz, jr. Federal University of São Carlos - Brazil   UFSCar-Campus Sorocaba Rod. João Leme dos Santos, Km 110-SP 264 Bairro Itinga Sorocaba, SP 18052-780 Brazil   cesarcruzjr@gmail.com   https://www.ppgec.ufscar.br/           JEL Areas: Q : Agricultural and Natural Resource Economics C4 : Econometric and Statistical Methods: Special Topics