(9) INCOME TAXES

Our income tax is different than the expected amount computed using the applicable federal and state statutory income tax rates. The reasons for and effects of such differences for the years ended December 31 are below (in thousands):


	2019		2018
Expected amount	$	(17,262)	$	737
State income taxes, net of federal benefit		(3,831)		(654)
Percentage depletion		(1,475)		(3,278)
Stock-based compensation		326		(15)
Captive insurance		(271)		—
Return to provision adjustments		(78)		(592)
Other		244		(273)
	$	(22,347)	$	(4,075)

The deferred tax assets and liabilities resulting from temporary differences between book and tax basis are comprised of the following at December 31 (in thousands):


	2019		2018
Long-term deferred tax assets:
Net operating loss	$	18,956	$	17,194
Interest limitation carryforward		1,801		441
Capital loss carryforward		555		10
Alternative minimum tax credit		524		1,049
Stock-based compensation		135		613
Other		1,294		985
Total long-term deferred tax assets:		23,265		20,292
Coal properties		(27,884)		(46,733)
Net deferred tax liability	$	(4,619)	$	(26,441)

Our effective tax rate (ETR) for 2019 was 27% compared to (116)% for 2018. The negative ETR in 2018 is due mostly to the statutory depletion deduction which was in excess of our book income. The tax rate for the years ended December 31, 2019 and 2018 are not predictive of future tax rates. Historically, our actual ETRs have been lower than the statutory effective rate primarily due to the benefit received from statutory depletion allowances. The deduction for statutory depletion does not necessarily change proportionately to changes in income before income taxes.

We have analyzed our filing positions in all of the federal and state jurisdictions where we are required to file income tax returns, as well as all open tax years in these jurisdictions, to determine whether the positions will be more likely than not be sustained by the applicable tax authority. Tax positions not deemed to meet the more-likely-than-not threshold are not recorded as a tax benefit or expense in the current year. We identified our federal tax return and our Indiana state tax return as “major” tax jurisdictions. We believe that our income tax filing positions and deduction will be sustained on audit and do not anticipate any adjustments that will result in a material change to our consolidated financial position. While not material, we record any penalties and interest as SG&A. Tax returns filed with the IRS and state entities generally remain subject to examination for three years after filing.

At December 31, 2019, we had approximately $68 million and $100 million of federal and Indiana net operating loss carryforwards (“NOLs”), respectively. These NOLs are available to offset future taxable income. Federal NOLs generated in 2017 and prior years have a carryforward period of 20 years while those generated in 2018 and future years carryforward indefinitely. The federal NOLs will expire in varying amounts from 2035 to 2037 if they are not utilized. Indiana NOLs have a 20-year carryforward period and will expire in the years 2034 to 2039 if they are not utilized.