Will the New-style Currency Decrease Counterfeiting?-The Effect of Withdrawal Policy

Abstract

A common policy to decrease counterfeiting is to introduce new-style currency that is harder and more expensive to counterfeit. Upon introducing new-style currency, government may withdraw old-style currency from circulation with or without imposing a deadline for private holders to exchange old-style money for new-style. The withdrawal policy affects the length of time it takes for the removal of old-style currency to be completed and, thus, have impacts on the effectiveness of decreasing counterfeiting. We use a random matching model to study the effect on stopping counterfeiting of different withdrawal policies accompanying the issue of new-style currency. We find that, if the enforcement effort against counterfeiting is not high enough, the introduction of new-style currency will not achieve a steady state where counterfeiting is eliminated. If government withdraws old-style currency more aggressively, it takes a shorter time to eliminate counterfeiting. However, seeing the counterfeit money start to decrease, government should not make a premature judgment that the policy of eliminating counterfeiting has achieved its purpose. If government wrongly makes the judgment and decreases its effort in confiscating counterfeit money as well as withdrawing old-style currency, the counterfeiting problem may resume.

一國政府為保有鑄幣利得，常以發行新版鈔票來解決?鈔問題。而各國施行鈔票改版政策所採取的舊鈔回收規定迥異，例如是否設定回收截止期限，以及執行回收機構的多寡等，都將使得回收舊鈔兌換新鈔的速度不同。本文以貨幣搜尋模型探討不同的舊鈔回收規定如何影響鈔票改版政策解決?鈔問題的有效性，以及?鈔問題獲得解決的時點。我們發現，當糾舉?鈔、回收舊鈔的績效太低，發行新版鈔票無法解決?鈔問題；足夠的糾舉績效是杜絕?鈔的關鍵。若政府採行的舊鈔回收規定可迅速回收舊鈔，則鈔票改版解決?鈔問題的政策效果將較早發生。不過，政府若看到?鈔數量減少便過早判定?鈔問題已銷聲匿跡，而提早回收截止期限甚至降低查緝?鈔的努力，都可能使?鈔問題死灰復燃。