Take India. TI ranks it 94th out of 174 countries. But of the 93 countries that have a better corruption ranking, as many as 86 also do better on per capita income. Only seven countries that are poorer than India manage to do better on corruption. Six of them, interestingly, are in Africa (Rwanda, Lesotho, Liberia, Zambia, Malawi and Burkina Faso), so parts of that continent are doing some things better than us in India. Look then at the South Asia corruption scores, and the picture is generally consistent: corruption perceptions usually improve as incomes rise. Bhutan has the second highest per capita income (INR127,050) and also the best corruption rank (33). That is followed by Sri Lanka (INR178,228 and rank of 79), and then India (INR93,508 and corruption rank of 94). The poorer neighbours (Pakistan, Bangladesh, Nepal) also do worse on corruption, ranking between 139 and 144. The moral in the numbers seems to be clear: get rich and your country is also likely to become clean (or at least cleaner).
(Source: “Weekend Ruminations” by T.N. Ninan in Business Standard dated 08-12-2012)