it works well with my 3.5 and 5 year olds. though i am a bit worried they think the world turns on pasta now. we went to the school fete at the weekend, they had been "earning" pasta all week to "spend" at the fete. but dd1 would not let me convert it into money (10p per pasta piece, i was offering) but insisted on taking the pasta with her and she even used it to pay to get into the fete!
Something we found worked well was having pasta jars for the grown ups too. my dds love the equity of this. if we swear, or shout unnecessarily, we lose a bit of pasta. etc.