Margin Requirements, Price Fluctuations, and Market Participation in Metal Futures
研究发现金属期货的保证金要求会减少市场参与，且这种影响是因果性的；保证金与未来波动正相关，但可能源于交易所的选择性调整。
Margin requirements in metal futures contracts have a negative impact on market participation that seems causal because it is absent from a benchmark group of metals that do not undergo similar margin changes. It is less clear whether margins restrict primarily rational or irrational investors. The stronger positive relation between margins and future target metal volatility than benchmark metal volatility can simply be attributed to the selection rule of the exchanges, as they increase margins in those metals for which they anticipate a comparatively higher future volatility. Copyright 1995 by Ohio State University Press.