Many sinkie PMETs I know switch to teaching because it is one of the few civil service jobs that will pay at a PMET rate all the way till retirement. More and more sinkie PMETs realize that they cannot hack it in the private sector against more talented and efficient foreigners. Hence, they are smart enough to quickly join teaching, before they lose all their knowledge and have to end up driving taxis or working as security guards at 40 years old.