Goodwill implications

In practical terms, this will mean that the PBV ratios of acquisitive companies will generally look lower (and more attractive from an investment standpoint) than nonacquisitive companies.

процентные ставки и multiples

The effect of changes in the expected growth rate on equity multiples can also vary depending on the level of interest rates. The value of growth lies in the future, and as interest rates rise, the value of expected growth decreases. Consequently, surprises about expected growth rates have a bigger impact when interest rates are low than when they are high. We would expect to see much greater price reactions for a given earnings surprise, positive or negative, in a low-interest-rate environment than you would in a high-interest-rate environment. 

Aswath Damodaran "On valuation" 

so should i short Groupon then?

My problem with selling short has always been that I don’t control my time horizon; the person who has lent me the shares does. After all, even if you are right in your assessments of value, you will not make money until the market corrects its “mistakes” and that may take weeks, months or even years.

Aswath Damodaran on selling short the stock you perceive as overvalued 

искусство прикладной оценки

Aswath Damodaran on risk-free rates in current environment
Если немного вырвать из контекста: 

The risk free rate is a reflection of what people expect in the overall economy for the foreseeable future. Harking back to an equation that I have used before, note that the risk free rate is the sum of two market expectations: an expectation of inflation for the future and an expectation of real growth.

Risk free rate = Expected inflation + Expected real growth

Viewed through these lens, it is quite clear that a very low risk free rate is not generally compatible with a vibrant high growth economy. In fact, the biggest factor driving down ten-year bond rates this year from 3.29% to 2% has been the increasing pessimism about global economic health, pushing down both expected real growth and expected inflation. That is the basis for my argument that the Fed has become a side player in this game and that its push for lower risk free rates is actually at odds with its desire that the US return to healthy economic growth.