I Quant NY is a Tumbler dedicated to New York City data stories.

It generally relies on the city’s Open Data sets, but this story started with an article in BusinessWeek about taxi tipping. The reporter actually had to request the data, and then showed some stuff that I Quant NY had trouble with.

The result is a wonderful (and I use that term precisely, though I know it is also funny) detective story investigated through math, and nailed with actual evidence: receipts! It won’t spoil things if reveal that a sizable if possibly unintentional fraud is involved.

Wonderful, really.