It is definitely not new, and not Paper Moon (that was shot in black & white, wasn't it?).Danger said:If you're thinking of a new one, 'Matchstick Men' with Nicolas Cage and Alison Lohman was about a con man and his daughter. I haven't seen it, so I don't know if it includes short-change artistry.
A much older movie along the same line was 'Paper Moon' with Ryan and Tatum O'Neal, followed by a spin-off series with Christopher Connelly and Jodie Foster.
It's really bugging me - I can even picture the short-change scene (small store, middle-aged woman at the till, the villian engaging in smooth chitchat (doing a great job of distracting), and the camera lingering on the woman's face after the scamsters have left ... puzzled, thinks something fishy has been going on but can't quite put her finger on it). The other scam was to give the young girl (in cahoots with our villian) a $20 (?) bill with a 'pull the heartstrings' note in pen on it, and after using it pay for something she breaks down in tears over having her 'dear aunty's note' taken from her, while our villian shames the victim into parting with the note.