Every year Transparency International compiles information from different surveys and indices to create its now famous corruption perceptions index (CPI).  Considering that CPI scores and rankings are a rough proxies for actual corruption, Thailand's position has not changed much.  Last year countries were scored from 0 (most corrupt) to 10 (least corrupt).  Last year Thailand scored 3.4, while this year on a new 0 to 100 scoring system, Thailand scored 37.  Last year Thailand ranked 80, while this year it ranked 88, a ranking shared with Malawi, Morocco, Suriname and Zambia.  

Singapore, ranked at  5 with a score of 87, was (again) perceived in the ratings as the least corrupt country in Southeast Asia.  Denmark, Finland and New Zealand scored 90 and shared the top ranking. Again, no surprises. Generally speaking, with the exception of New Zealand, Scandinavian and North European countries tend to dominate the top rankings, reflecting the perception that these are among the least corrupt countries in the world.  They are also among the most affluent countries in the world.  

In general, survey after survey shows a strong correlation between wealth, income equality and transparency.  The opposite is also true: surveys consistently show that poverty, income inequality and corruption all tend to correlate with each other.  In Southeast Asia, Singapore and Hong Kong are considered the least corrupt countries and both countries are, by a wide margin, the most affluent countries in the region.