9 Income taxes

A reconciliation between tax expense and the product of accounting income multiplied by the basic income tax rate for the years ended December 31, 2019 and 2018 is as follows:


	2019			2018
Loss before income taxes	$	(55,285)		$	(23,111)
Basic income tax rate		26.30	%		26.67	%
Computed income tax recovery		(14,542)			(6,164)
Effect on income tax rate resulting from
Accounting charges not deductible for tax purposes		23			12
Non‑deductible share‑based compensation		317			169
Share issue costs		(2,739)
Unrecorded potential tax benefits of current period losses and other tax assets		16,829			6,183
Non‑refundable investment tax credit used (earned) in the year		—			(145)
Valuation allowance for prior year adjustment		77			—
Other		(21)			19
Income tax expense (recovery)/expense reported in the consolidated statements of loss and comprehensive loss	$	(56)		$	74

The Company has incurred Canadian federal and provincial net operating losses (NOLs) from inception. As of December 31, 2019, the Company has NOL carry‑forwards of approximately $86,591 and $86,085, respectively, for Canadian federal and Québec purposes, available to reduce future taxable income, which expire beginning in 2027 through 2039. The Company also has scientific research and experimental development expenditures of approximately $9,377 and $11,127, respectively, for Canadian federal and Québec income tax purposes, which have not been deducted. These expenditures are available to reduce future taxable income and have an unlimited carry‑forward period. Research and development tax credits and expenditures are subject to verification by the tax authorities, and, accordingly, these amounts may vary.

The Company has incurred NOLs for U.S. tax purposes. As of December 31, 2019, the Company has carry-forwards of approximately $12,439 related to U.S. NOLs that may be carried forward indefinitely and are available to reduce future taxable income.

Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. The net deferred tax assets have not been recognized in these financial statements because the criteria for recognition of these assets were not met.

The Company’s deferred tax assets consist of the following for the years ended December 31, 2019 and 2018:


	2019	2018
Net operating loss carry‑forwards	25,965	12,209
Tax basis of property and equipment in excess of carrying values	103	93
Federal SR&ED investment tax credits	535	273
Taxation of federal SR&ED investment tax credits	(142)	(72)
Research and development expenditures	2,686	1,791
Financing costs	2,103	138
Others	16	21
Total gross deferred tax assets	31,266	14,453
Valuation allowance	(31,266)	(14,453)
Net deferred tax assets	—	—

The Company files income tax returns in Canada and in the United States. The Company is subject to Canada Revenue Agency and Revenu Québec examination for fiscal years 2014 to 2019 due to unexpired statute of limitation periods and is subject to US Federal and state income tax examination for fiscal years 2017 to 2019.