读一篇电力市场经济和管制的文章有几个问题, 请教大家

1. 文章中写到SMA(supply margin assesment) 和RSI (residual supply index)的区别
Weakness of SMA:
1]Overly restrictive and disqualifies a supplier for a single hour (peak hour)
2]Does not account for operating reserve margin requirement
3]Ignores the net buyer or seller position of a supplier and the possible collusion between suppliers

Advantage of RSI:
1]Allows for some hours where the threshold are exceeded to leave room for price fluctuation to reflect market situation, signal for conservation and new investment
2]Higher threshold of 110% accounts for possible collusion
3]Nets out capacity contracted to load under long-term fixed prices
4]Allows distinction between net buyers and net sellers in the markets
5]Threshold can be adjusted based on actual market experience
我是初学经济的, 不能理解上述分析的意思

2. 为什么the inverse of HHI is the number of effective competitors, 这个是经验值还是有数学证明?
希望高手讲解一下, 或者告诉我还可以把这些问题发到哪个相关专业版块,谢谢