My informant is a 19 year old student studying neuroscience at USC.
“One short family tradition that my family has – which I don’t know if it’s like a Filipino thing or like a world-wide thing – but, basically any time that you give someone a gift that is a bag, or uh like a purse or wallet or something like that, you always, we always put a one dollar bill in it for good luck. Um, yeah I don’t know why, but that’s just what we do, so anytime I give a gift that’s a bag, I always put a one dollar bill or one dollar coin in it.”
This is a common tradition for people world-wide. It can be seen as rude to gift a purse or wallet that is empty. This can be interpreted as the giving the gift receiver bad luck if it is an empty wallet or purse, cursing them to have no money.