Efficacy
Pen manufacturers claim such pens will detect a great majority of counterfeit bills, but critics suggest the effectiveness is much lower. Critics claim that professional counterfeiters use starch-free paper, making the pen unable to detect the majority of counterfeit money in circulation. Magician and skeptic James Randi has written about the ineffectiveness of counterfeit pens on numerous occasions and uses a pen as an example during his lectures. Randi claims to have contacted a United States Secret Service inspector and asked whether the pen works as advertised, to which the inspector replied "it is not dependable." The Secret Service does not include such pens in their guidelines for the public's detection of counterfeit US currency.
US counterfeiters bleach small denominations and print more valuable bills on the resulting blank paper to evade this test, although changes to the currency since 2004 have made this method easier to detect. This is one reason that many currencies use different sized notes for different denominations.
Read more about this topic: Counterfeit Banknote Detection Pen
Famous quotes containing the word efficacy:
“For books are not absolutely dead things, but do contain a potency of life in them to be as active as that soul was whose progeny they are; nay, they do preserve as in a vial the purest efficacy and extraction of that living intellect that bred them. I know they are as lively, and as vigorously productive, as those fabulous dragon’s teeth; and being sown up and down, may chance to spring up armed men.”
—John Milton (1608–1674)
“If there is a case for mental events and mental states, it must be that the positing of them, like the positing of molecules, has some indirect systematic efficacy in the development of theory.”
—Willard Van Orman Quine (b. 1908)