Low coercivity results when you use Gamma Ferric Oxide magnetic particles and high coercivity results when you use Barium Ferrite magnetic particles. Coercivity indicates by measure how difficult it is to encode information onto the magnetic stripe. For those who think that the metric system is challenging, coercivity is measured in Oersteds or Oe. Although, one may question if a magnetic stripe is created in order to place information on it then why in the world would you want to make technology more difficult by varying Oersteds or coercivity; in that if you make it very difficult to encode information on magnetic stripes, then what is the point of creating them for use by the general public? Technology, needs to stay with an easier process as the liason for people and machines. Hence, bank cards have low coercivity, which means that it is easier to get your information encoded onto the card so and now you have a piece of technology to use for banking purposes 24/7 as opposed to waiting for a bank teller to show up; during normal business hours.
The concern between low coercivity and high coercivity is about something as simple as a magnet. Which can be used to erase information on the magnetic stripe of low coercivity as opposed to that of a high coercivity magnetic stripe. A solution to that would be to develop wallets, card holders and purses with card pockets that protect cedit cards, bank cards, airline tickets and transit tickets ect. from exposure to magnetic objects or anything that can demagnetize. That way the incidence of erasure would be greatly reduced and incidentally the magnetic stripe would last much longer.
ATM machines or readers of magnetic stripe cards should have indicators on them that inform
the card owner if the stripe signal is good, otherwise known as signal amplitude. As the card passes through a reader, signal indicators can provide somewhat of a warning as to the remaining use of a card due to the wear and tear of the magnetic stripe on it. That same good or bad stripe can be determined once we go to place the card in a reader and the reader is unable to read the card. Who knows? It could also be the machine you are using. But, if you place your card in a reader that has a signal amplitude indicator and it shows that the magnetic stripe although being able to be read; is providing a weak signal to the reader the card owner will know it's time to obtain another card and transit personel will know that hey, you're not looking for a free ride(some of us always have to pay), the stripe is just worn out!