A few thoughts ...
It appears that they are using gross before tax income to calculate the percentages. When you consider that the real (take home) income of the "Wealthy" is far lower (as a percentage) than their before tax income due to high tax rates, and the real (take home) income of the "Poor" is far higher (as a percentage) than their before tax income due to tax credits and welfare, it is very likely that the ratios would be closer if you calculated them based on after tax income.
Also notice that they are only counting cash donations to charities as giving to charities, which makes it difficult to really make a claim that one group is more charitable than another. When you factor in bake-sales, charity auctions, events, and lotteries/raffles there are a lot of ways people can give money to charity which is not (necessarily) a cash donation to a charity; beyond that, how do you calculate the value of the donation of food or clothing? If a "rich" person buys $20 worth of food every time they go grocery shopping and drops it into the food donation box anonymously how would that be tracked?
There is also the question of how they would CEOs of large corporations who choose to make $1 per year and, in many cases, donate tens or hundreds of millions of dollars to charity factor into the statistics? If a person donates $452,833,000.00 (a value representing 1 Million average "poor people" donations) and only earns $1 per year wouldn't that heavily impact the statistics?
What about corporations, how are their donations included? Does the 'Product Red' products count as a donation from companies like Apple, from the person who bought the product, or are they not considered charitable?
Just more evidence that lying with statistics is easy, and there is a far greater need for further education in statistics in grade school.
