Samra 2, their is no culture of tipping taxi drivers in BA. You need not follow "American" culture of tipping cab drivers in BA and no cab driver expects it, here. ( well..maybe he does when he sees a stupid gringo).
However, if thats what you are used to doing, please go ahead and continue to do it..if it makes you feel good about your 'karma'. But their are lot of poor people worldwide with no work, shelter, medicines, food and water. They surely can do with some of that extra money you may have available, at your disposal, for giving out.
Charity to a stranger with nothing recieved in reciprocity will do wonders for your "karma".
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Although when you go to NY for NYE , be prepared to tip every cab driver 18% or more and if you don't, then please be ready to be abused/yelled at and be threatened.
