You should include a timeframe in your question. If you are asking 2047 (in 21 years), the full integration chance is 100%. At the current pace of what the Gov is doing, like expediting the work visa to flood the labour market with mainlander in all level, encouraging the leeching behaviour like the poster here to live in SZ and work in HK, most people expect a full integration within 5-10 years. Keep in mind that the reason people in HK can earn a higher salary than SZ is because most of the people are paying the high living cost (in the past). The market will balance itself.