Every year, the group does a global survey of citizens and experts to get their views on how honest or crooked different institutions are in their country, from the police to lawmakers.
Because bribery, kickbacks, nepotism and other forms of corruption are clandestine activities, measuring public opinion about local graft is one of the few ways researchers have of getting a handle on the scale of the problem.
On a scale of zero to 100, with zero being the most corrupt and 100 the cleanest, North Korea and Somalia each scored eight. Afghanistan came next with 11, followed by Sudan with 12.
North Korea and Somalia were also the worst-ranking countries from 2011 to 2014 (though they tied with Afghanistan in 2012 and 2013).
It may not come as much of a surprise that Scandinavia and New Zealand are among the best in the list, with Denmark being judged the world’s least corrupt nation for the second year running, scoring 91.
Of the world’s 10 most crooked nations, most have experienced wars recently, including Afghanistan, Iraq, Sudan and Libya. North Korea and Venezuela are notable exceptions, though both countries have all kinds of other internal strife.
Brazil took the biggest dive toward total corruption in 2015, compared to the 2014 index. The South American giant has been roiled by a series of multibillion-dollar scandals that have seen some of its most powerful politicians and business leaders arrested.
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But relatively clean nations shouldn’t feel smug, the report warns. That’s because even though they enjoy high levels of public transparency and accountability, many of their corporations end up paying bribes when operating in poorer nations, fueling the corruption there. 
by Simeon Tegel, GlobalPost
This article is syndicated from GlobalPost.