(21)

Common stock

Changes in Berkshire’s issued, treasury and outstanding common stock during the three years ending December 31, 2018 are shown in the table below. In addition to our common stock, 1,000,000 shares of preferred stock are authorized, but none are issued.


	Class A, $5 Par Value (1,650,000 shares authorized)									Class B, $0.0033 Par Value (3,225,000,000 shares authorized)
	Issued			Treasury			Outstanding			Issued		Treasury			Outstanding
Balance December 31, 2015		820,102			(11,680	)		808,422			1,253,866,598		(1,409,762	)		1,252,456,836
Conversions of Class A common stock to Class B common stock and exercises of replacement stock options issued in a business acquisition		(32,044	)		—			(32,044	)		49,457,329		—			49,457,329

Balance December 31, 2016		788,058			(11,680)			776,378			1,303,323,927		(1,409,762	)		1,301,914,165
Conversions of Class A common stock to Class B common stock and exercises of replacement stock options issued in a business acquisition		(25,303	)		—			(25,303	)		38,742,822		—			38,742,822

Balance December 31, 2017		762,755			(11,680	)		751,075			1,342,066,749		(1,409,762	)		1,340,656,987
Conversions of Class A common stock to Class B common stock and exercises of replacement stock options issued in a business acquisition		(20,542	)		—			(20,542	)		31,492,234		—			31,492,234
Treasury stock acquired		—			(1,217	)		(1,217	)		—		(4,729,147	)		(4,729,147	)

Balance at December 31, 2018		742,213			(12,897	)		729,316			1,373,558,983		(6,138,909	)		1,367,420,074

Each Class A common share is entitled to one vote per share. Class B common stock possesses dividend and distribution rights equal to one-fifteen-hundredth (1/1,500) of such rights of Class A common stock. Each Class B common share possesses voting rights equivalent to one-ten-thousandth (1/10,000) of the voting rights of a Class A share. Unless otherwise required under Delaware General Corporation Law, Class A and Class B common shares vote as a single class. Each share of Class A common stock is convertible, at the option of the holder, into 1,500 shares of Class B common stock. Class B common stock is not convertible into Class A common stock. On an equivalent Class A common stock basis, there were 1,640,929 shares outstanding as of December 31, 2018 and 1,644,846 shares outstanding as of December 31, 2017.

Since we have two classes of common stock, we provide earnings per share data on the Consolidated Statements of Earnings for average equivalent Class A shares outstanding and average equivalent Class B shares outstanding. Class B shares are economically equivalent to one-fifteen-hundredth (1/1,500) of a Class A share. Average equivalent Class A shares outstanding represents average Class A shares outstanding plus one-fifteen-hundredth (1/1,500) of the average Class B shares outstanding. Average equivalent Class B shares outstanding represents average Class B shares outstanding plus 1,500 times average Class A shares outstanding.

For several years, Berkshire had a common stock repurchase program, which permitted Berkshire to repurchase its Class A and Class B shares at prices no higher than a 20% premium over the book value of the shares. On July 17, 2018, Berkshire’s Board of Directors authorized an amendment to the program, permitting Berkshire to repurchase shares any time that Warren Buffett, Berkshire’s Chairman of the Board and Chief Executive Officer, and Charlie Munger, Vice Chairman of the Board, believe that the repurchase price is below Berkshire’s intrinsic value, conservatively determined. The program continues to allow share repurchases in the open market or through privately negotiated transactions and does not specify a maximum number of shares to be repurchased. However, repurchases will not be made if they would reduce the total value of Berkshire’s consolidated cash, cash equivalents and U.S. Treasury Bills holdings below $20 billion. The repurchase program does not obligate Berkshire to repurchase any specific dollar amount or number of Class A or Class B shares and there is no expiration date to the program.