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).
Answer Wiki. The Integrated Circuit Chip ID or ICCID (this is the 19 or 20 digits printed on the SIM) is not necessarily related to the IMSI - this is not a requirement of the cellular standards. The ICCID is only for the specific SIM card during manufacturing and is not changed.