20论坛币，请大家帮忙翻译几个英语！！

10论坛币，请大家帮忙翻译几个英语！！    谢谢大家！！
   Tier 1 Risk Adjusted Capital Ratio
MB = Market Value of Equity/ Book Value of Equity
Market-to-book

Slack = Cash and marketable securities/Total Assets

Stulz (1996, 2003) argues that any potential value creation role for riskmanagement is in the reduction or elimination of “costly lower-tail outcomes.”                  costly lower-tail outcomes  是什么意思啊？

根据正态分布的正负3西格玛理论，99.55%的样本是在正负3西格玛理论，超出这个范围的样本数很少，单是他们离mean很远，所以叫 lower-tail outcomes，costly 的意思是因为离mean偏差大，所以一旦出现，带来的risk 成本高。我这是翻译+科普啊。对了，同学标题上是20个币，怎么进来就成10个了？