BEST BUY CO INC | 2013 | FY | 3

In fiscal 2013 (11-month), 2012 and 2011, we estimated the fair value of stock-based compensation expense associated with our employee stock purchase plans on the purchase date using the Black-Scholes option-pricing valuation model, with the following assumptions:
 
 
11-Month
 
12-Month
Valuation Assumptions
 
2013
 
2012
 
2011
 
 
 
 
 
 
 
Risk-free interest rate(1)
 
0.1
%
 
0.1
%
 
0.2
%
Expected dividend yield
 
2.9
%
 
2.4
%
 
1.4
%
Expected stock price volatility(2)
 
41
%
 
38
%
 
29
%
Expected life of employee stock purchase plan options (in months)(3)
 
6

 
6

 
6

(1)
Based on the U.S. Treasury constant maturity interest rate whose term is consistent with the expected life of employee stock purchase plan shares.
(2)
We consider both the historical volatility of our stock price as well as implied volatilities from exchange-traded options on our stock.
(3)
Based on semi-annual purchase period.

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