A general rule of thumb is that if your economic model has no value judgements, it's positive economics, and if it does have value judgements it's normative economics, since to tell someone what he ought to do, you first have to judge what is best for him.
A subscriber identity module or subscriber identification module (SIM) is an integrated circuit that is intended to securely store the international mobile subscriber identity (IMSI) number and its related key, which are used to identify and authenticate subscribers on mobile telephony devices (such as mobile phones and computers).
EMV card. An EMV card, also called a chip-and-PIN card or smart card, contains a special computer chip to store card account data. Unlike magnetic-stripe cards, every time an EMV card is used for payment, the chip creates a unique transaction code that cannot be reused, thus stymying counterfeit card fraud.