Salary is one factor, but environment is another big factor as well.

Say you are a high ranking teacher, living in rural area, where your relatives are, no KPI, good environment, no punch card/can get home by 430pm. You offer the person double pay, but must be in KV, don't think the person wants the promotion. I have met few people like this. No longer want/scared to get promoted since they are happy where they are.

Another factor is job satisfaction. Old company, boss, get to dictate workflow, vs new company 20% increase pay, but kuli have to do all the work. Depends on age. Do you really need the extra income.

If in the same area, say KV, same job scope, then 30% minimum with yearly increments, better work benefits than current job