Equity Plans

As of November 29, 2018, 115 million shares of our common stock were available for future awards under our equity plans.

Stock Options

Stock options granted and assumptions used in the Black-Scholes option valuation model were as follows:



Quarter ended	November 29, 2018			November 30, 2017
Stock options granted	—			1
Weighted-average grant-date fair value per share	$	19.50		$	17.67
Average expected life in years	5.4			5.6
Weighted-average expected volatility	44		%	44		%
Weighted-average risk-free interest rate	2.9		%	2.1		%
Expected dividend yield	0.0		%	0.0		%

Restricted Stock and Restricted Stock Units ("Restricted Stock Awards")

Restricted Stock Awards activity is summarized as follows:



Quarter ended	November 29, 2018		November 30, 2017
Restricted stock award shares granted	6		2
Weighted-average grant-date fair value per share	$	39.02	$	39.01

Stock-based Compensation Expense



Quarter ended	November 29, 2018		November 30, 2017
Stock-based compensation expense by caption
Cost of goods sold	$	26	$	20
Selling, general, and administrative	19		18
Research and development	16		13
	$	61	$	51

Stock-based compensation expense by type of award
Restricted stock awards	$	41	$	34
Stock options	12		17
Employee Stock Purchase Plan	8		—
	$	61	$	51

Income tax benefits related to share-based payment arrangements were $23 million and $57 million for the first quarters of 2019 and 2018, respectively. Income tax benefits related to share-based compensation for the first quarter of 2018 were offset by an increase in the U.S. valuation allowance. As of November 29, 2018, $498 million of total unrecognized compensation costs for unvested awards, before the effect of any future forfeitures, was expected to be recognized through the first quarter of 2023, resulting in a weighted-average period of 1.4 years.