The Tax Cuts and Jobs Act was enacted on December 22, 2017. Among other things, the new law (i) establishes a new, flat corporate federal statutory income tax rate of 21%, (ii) eliminates the corporate alternative minimum tax and allows the use of any such carryforwards to offset regular tax liability for any taxable year, (iii) limits the deduction for net interest expense incurred by U.S. corporations, (iv) allows businesses to immediately expense, for tax purposes, the cost of new investments in certain qualified depreciable assets, (v) eliminates or reduces certain deductions related to meals and entertainment expenses, (vi) modifies the limitation on excessive employee remuneration to eliminate the exception for performance-based compensation and clarifies the definition of a covered employee and (vii) limits the deductibility of deposit insurance premiums. The Tax Cuts and Jobs Act also significantly changes U.S. tax law related to foreign operations; however, such changes do not currently impact us.

As stated above, as a result of the enactment of the Tax Cuts and Jobs Act on December 22, 2017, we remeasured our deferred tax assets and liabilities based upon the newly enacted U.S. statutory federal income tax rate of 21%, which is the tax rate at which these assets and liabilities are expected to reverse in the future. Notwithstanding the foregoing, we are still analyzing certain aspects of the new law and refining our calculations, which could affect the measurement of these assets and liabilities or give rise to new deferred tax amounts.

	Three Months Ended March 31,
	2019			2018
Income tax expense for the period	$	1,187		$	944
Effective tax rate		18.19	%		17.80	%

The effective tax rates differ from the statutory federal tax rate of 21% for the three months ended March 31, 2019 and 2018, largely due to tax exempt interest income earned on certain investment securities and loans and the nontaxable earnings on bank owned life insurance.