You can't find staff to work for minimum wage in HK anyway. HK staff are expensive and the work product isn't that great. I've started hiring in other cheaper countries with much better results and people who are thankful to be employed.
Civil servant's non-performance related raises should be tied into a published index, which is also used for setting the minimum wage.
I also think (and not sure if this exists anywhere) that the cost of living indexes should be tiered by income - people who are in lower earnings brackets have different inflationary issues than say an executive officer or middle tier manager in the civil service.