September 15th, 2009, 9:12 am
Interesting question.A call option gives you the right to buy a thing for a certain amount of money.If the gift certificate gave you the right to buy a certain toy for $5 then you could model it as a call option and the infinite duration option would be more valuable than the month option.The month duration option would probably be worth a couple of cents - all depending on how volatile toy prices are.But as knightrider says, you don't have a call option.But the tools of financial mathematics might not be the best place to start here. Maybe we should start by talking behavioural economics.Rationally a gift certificate makes no sense unless it is sold at a discount to the face value. It is a restriction of choice, product 2 being the most restrictive. But is it also a 'gift', which is a product with a value different from the purchasing power of it's $5 face value. The fact that there is a restriction on the store the $5 can be spent in actually adds value to the product. The store restriction is the gift, as it comes with a nice bit of thick paper normally with shiny writing on it and the words 'gift' printed somewhere.The month restriction is not part of this 'gift' premium. How should we value that. Maybe by looking at the second hand market for gift certificates on ebay? Or maybe by researching how gift certificates are spent. How many gift certificates are never redeemed? Does this change depending on the duration of the gift certificate? Basically is there a real market in second hand gift certificates, or in practice do people value the idea of the gift and disregard the monetary value?