How to check global and local maximum?

[yli725]

Dear Tom,

After I use MLE to estimate the MVGarch model, how can I check the global or local maximum? Thank you very much!

[TomDoan]

With any model whose likelihood function isn't known to be globally (quasi-) concave, there is no way to tell for certain if you've found a local or a global maximum. If you're concerned about it, you can use preliminary GENETIC iterations to see if they find a different optimum.