The individual rationality of buying small cokes/chippies
One of the most vexing questions in economics has to be why the price of a 330ml coke is often only slightly less than the price of a 1.5l coke. This issue generalises to other products such as chippies.
Now there are a number of good responses, namely:
- Strongly diminishing marginal utility for fresh coke and a very low value on saved coke (or a relatively high cost of storage),
- A 330ml bottle is easier to consume than a 1.5l bottle – as a result the value of the 330ml bottle may be higher for people on the move, and so they are priced to service different markets.
- The cost of producing a 330ml coke is far more than a 33/150th of the cost of producing a 1.5l coke
These answers seem to satisfy me when I think of coke. However, when I think of chippies I find this explanation sadly lacking.
Downstairs I can buy a little bag of chippies for $1.50 or a far bigger bag of chippies (x3) for $3.00. I always buy the little bag.
Now I will do this each day, and don’t get any less value from 3 day old chippies than I do fresh chippies. Furthermore, I am eating them at work – implying that there is no storage cost and no convenience benefit.
No-one steals my chippies if I get a big packet so its not that. Am I passing up a free lunch here (and thereby not being a utility maximiser as my shirt says) – or is there a reason I buy the small bag instead of the big bag.