8. Stock-Based Compensation

Since the date of its effectiveness on May 5, 2016, the Company issues new grants of stock-based awards pursuant to the Dawson Geophysical Company 2016 Stock and Performance Incentive Plan (the “2016 Plan”). All of the Company’s prior plans have expired pursuant to their terms and no awards previously granted under prior plans remain outstanding. The awards outstanding and available under the 2016 Plan and their associated accounting treatment are discussed below.

In 2016, the Company adopted the 2016 Plan, which provides for the issuance of up to 1,000,000 shares of authorized Company common stock. As of December 31, 2019, there were approximately 330,861 shares available for future issuance. The 2016 Plan provides for the issuance of stock-based compensation awards, including stock options, common stock, restricted stock, restricted stock units and other forms. Stock option grant prices awarded under the 2016 Plan may not be less than the fair market value of the common stock subject to such option on the grant date, and the term of stock options shall extend no more than ten years after the grant date. The 2016 Plan terminates May 5, 2026.

Historically, the Company’s employees and officers that held unvested restricted stock were entitled to dividends when the Company paid dividends. The Company’s employees and officers that hold unvested restricted stock awarded during 2016 or thereafter are not entitled to dividends when the Company pays dividends.

Impact of Stock-Based Compensation

The following table summarizes stock-based compensation expense (in thousands), which is included in operating or general and administrative expense, as appropriate, in the Consolidated Statements of Operations and Comprehensive Loss for the years ended December 31, 2019, 2018 and 2017:


	Year Ended December 31,
	2019		2018		2017
Restricted stock awards	$	893	$	915	$	495
Restricted stock unit awards		15		122		161
Common stock awards		297		331		320
Total compensation expense	$	1,205	$	1,368	$	976

Stock Options

A summary of the outstanding stock options as of December 31, 2019 as well as activity during the year then ended is as follows:


	Number of Stock Options		Weighted Average Exercise Price		Weighted Average Remaining Contractual Term in Years
Balance as of December 31, 2018		87,497	$	11.23
Forfeited		—	$	—
Expired		(87,497)	$	11.23
Balance as of December 31, 2019		—	$	—		—
Exercisable as of December 31, 2019		—	$	—		—

Stock options issued under prior plans were a combination of incentive stock options and non-qualified stock options. For incentive stock options, no tax deduction is recorded when options are awarded. If an exercise and sale of vested options results in a disqualifying disposition, a tax deduction for the Company occurs.

Outstanding options at December 31, 2018 expired in July 2019. There were no unrecognized compensation costs related to stock options as of December 31, 2019.

There were no options granted or vested and no excess tax benefits from disqualifying dispositions during the years ended December 31, 2019, 2018 and 2017. No options were exercised during the years ended December 31, 2019, 2018 and 2017. No cash was received from option exercises during the years ended December 31, 2019, 2018 and 2017.

Restricted Stock Awards

There were no restricted stock grants in the years ended December 31, 2019, 2018 and 2017. The fair value of restricted stock awards equals the market price of the Company’s stock on the grant date and the awards generally vest in one to three years or in annual increments over three years.

A summary of the status of the Company’s nonvested restricted stock awards as of December 31, 2019 and activity during the year then ended is as follows:


	Number of Restricted Stock Awards		Weighted Average Grant Date Fair Value
Nonvested as of December 31, 2018		65,974	$	3.65
Vested		(65,974)	$	3.65
Nonvested as of December 31, 2019		—	$	—

As of December 31, 2019, there are no unrecognized compensation costs related to nonvested restricted stock awards.

The aggregate vesting date fair value of restricted stock for the years ended December 31, 2019, 2018 and 2017 was $255,000, $48,000 and $84,000, respectively.

Restricted Stock Unit Awards

The Company did not grant any restricted stock units for the year ended December 31, 2019. The Company granted 268,000 and 238,350 restricted stock unit awards during the years ended December 31, 2018 and 2017, respectively, with a weighted average grant date fair value of $7.14 and $3.96, respectively. The fair value of restricted stock unit awards equals the market price of the Company’s stock on the grant date and the awards generally vest in one to three years or in annual increments over three years.

A summary of the Company’s nonvested restricted stock unit awards as of December 31, 2019 and activity during the year then ended is as follows:


	Number of Restricted Stock Unit Awards		Weighted Average Grant Date Fair Value
Nonvested as of December 31, 2018		627,085	$	5.03
Granted		—	$	—
Vested		(197,485)	$	3.74
Forfeited		(19,500)	$	5.41
Nonvested as of December 31, 2019		410,100	$	5.64

As of December 31, 2019, there were approximately $871,000 of unrecognized compensation costs related to nonvested restricted stock unit awards. These costs are expected to be recognized over a weighted average period of 1.00 years.

The aggregate vesting date fair value of restricted stock units for the years ended December 31, 2019, 2018 and 2017 was $710,000, $273,000 and $422,000, respectively.

Common Stock Awards

The Company granted common stock awards with immediate vesting to outside directors and employees during the years ended December 31, 2019, 2018 and 2017 as follows:


	Number of Common Stock Awards		Weighted Average Grant Date Fair Value
Year ended December 31, 2019		119,556	$	2.48
Year ended December 31, 2018		59,284	$	5.59
Year ended December 31, 2017		67,498	$	4.74