This paper documents the fact that in options markets, the (percentage) implied volatility bid-ask spread increases at an increasing rate as the option's maturity date approaches. To explain this stylized fact, this paper provides a market microstructure model for the bid-ask spread in options...

Upstream producers that possess market power, sell forwards with a lengthy duration to regional electricity companies (REC). As part of the liberalization of the electricity market, RECs have been privatized and exposed to a possible bankruptcy threat if spot prices have fallen below their...