Parameter Estimation and Evaluation Maximum Likelihood Estimation Maximum Likelihood Estimation To find a global maximum,we need to check the second order condition(SOC):If the pxp sample Hessian matrix 立(0)= ∂2lni(0Xn) 80∂0' is negative definite for all0∈Θ，then0 is the global maximum. In many cases,it may be difficult to verify that H(O)is negative definite for all 0∈Θ. It is relatively straightforward to verify that H()is negative definite,which will imply that 0 is a local maximizer. Parameter Estimation and Evaluation Introduction to Statistics and Econometrics April 21,2020 25/207Parameter Estimation and Evaluation Parameter Estimation and Evaluation Introduction to Statistics and Econometrics April 21, 2020 25/207 Maximum Likelihood Estimation Maximum Likelihood Estimation