At the end of each interim period, the Company makes its best estimate of the annual expected effective income tax rate and applies that rate to its ordinary year-to-date earnings or loss. The income tax provision or benefit related to unusual or infrequent items, if applicable, that will be separately reported or reported net of their related tax effects are individually computed and recognized in the interim period in which those items occur. In addition, the effect of changes in enacted tax laws or rates, tax status, judgment on the realizability of a beginning-of-the-year deferred tax asset in future years or income tax contingencies is recognized in the interim period in which the change occurs.

The computation of the annual expected effective income tax rate at each interim period requires certain estimates and assumptions including, but not limited to, the expected pre-tax income (or loss) for the year, projections of the proportion of income (and/or loss) earned and taxed in respective jurisdictions, permanent and temporary differences, and the likelihood of the realizability of deferred tax assets generated in the current year. Jurisdictions with a projected loss for the year for which no tax benefit can be recognized due to a valuation allowance are excluded from the estimated annual effective tax rate. The impact of such an exclusion could result in a higher or lower effective tax rate during a particular quarter, based upon the composition and timing of actual earnings compared to annual projections. The estimates used to compute the provision or benefit for income taxes may change as new events occur, additional information is obtained or as our tax environment changes. To the extent that the expected annual effective income tax rate changes, the effect of the change on prior interim periods is included in the income tax provision in the period in which the change in estimate occurs.

A summary of the provision for income taxes and the corresponding effective tax rate for the three months ended March 31, 2021 and 2020, is shown below:

	Three Months Ended March 31,
	2021			2020
Income tax expense	$	7,565		$	5,406
Earnings before income tax	$	40,474		$	17,279
Effective tax rate		18.7	%		31.3	%

Income tax expense was $7,565 for the three months ended March 31, 2021, on earnings before income tax of $40,474, representing an effective tax rate of 18.7%. The effective tax rate differed from the U.S. Federal statutory rate of 21.0% primarily due to certain intercompany transactions in the first quarter of 2021, partially offset by the international provisions of the U.S. tax reform such as global intangible low-tax income (“GILTI”).

Income tax expense was $5,406 for the three months ended March 31, 2020, on earnings before income tax of $17,279, representing an effective tax rate of 31.3%. The effective tax rate differed from the U.S. Federal statutory rate of 21% primarily due to the international provisions of the U.S. tax reform, such as GILTI, partly offset by certain intercompany transactions which disproportionately benefited lower tax rate jurisdictions.