I am unable to comment on gov sector as one poster mentioned that you current boss will know that you are looking for another post. Nevertheless, job hop is good provided you have good reasoning especially in private sector. Personally my salary has jumped 70% on the 2 occasions that I job hop. It really depends on how you sell yourself and negotiate. One thing about government sector is that they know your pay grade. Whereas in private sector, if you are lucky, you can slightly inflate your pay and get away with it if HR never ask..