For an index, the P / B ratio is the weighted average of all the price / book ratios of stocks in the index. (us.beyondbullsandbears.com)
How do you determine what a fair price is to book ratio for any specific sector? (financialtrading.com)
I'm guessing that stocks in the drug sector would have a different price to book ratio from companies in the financial sector or Internet stocks. (financialtrading.com)