電子貨幣、地下經濟與最適政策

Abstract

本文使用具有現金與電子貨幣的貨幣搜尋模型分析電子貨幣的使用、政府經濟政策與地下經濟之間的關聯。模型中買家受到位置衝擊, 以外生給定的機率進入地下經濟或正規市場, 在兩個市場皆分別以Nash 議價決定價格與交易量。模型中有一具有投資技術的電子貨幣發行商, 將投資報酬回饋予電子貨幣的持有人。政府在此模型中透過貨幣供給和課徵消費稅影響經濟體。結果發現在通貨膨脹率和稅率足夠低的情況下, 現金與電子貨幣可以共存; 若通貨膨脹率或稅率太高便只有現金能夠流通。再者, 當政府的經濟政策使得通貨膨脹率或稅率上升, 會使得地下經濟的交易量相對正規市場的交易量提高。此外, 相較於純現金的經濟體, 現金與電子貨幣並存時, 社會總產量較高, 且政府可增加消費稅之稅收。

This paper analyzes the relation among the existence of e-money, official economic policies, and underground economy. In this model, each buyer receives a location shock and further enters whether underground economy or formal sector with a given probability. In addition, there is an e-money issuer who possesses investment technology and repays those who hold e-money with the return on investment. Besides, the government can affect the economy via either money supply or tax levy. As a result, if inflation rate and tax rate are sufficiently low, both cash and e-money exist; on the other hand, if either of them is too high, only cash circulates. The increase of inflation rate or tax rate will raise the transaction quantity of the underground economy comparing to the one of the formal sector. In comparison with pure cash economy, if cash and e-money coexist, the total transaction quantity would be higher, and the government would receive more revenue.