Note 13 — Retirement Plans

The components of net pension expense (income) for our global defined benefit plans were as follows:

	Three Months Ended January 31,						Nine Months Ended January 31,
	2019			2018			2019			2018
Service cost	$	226		$	243		$	688		$	715
Interest cost		6,103			6,407			18,484			19,005
Expected return on plan assets		(9,638	)		(9,924	)		(29,260	)		(29,363	)
Net amortization of prior service cost		(24	)		(24	)		(72	)		(72	)
Unrecognized net actuarial loss		1,429			1,536			4,337			4,550
Pension plan actuarial loss	$	—		$	—		$	—		$	21
Net pension income		(1,904	)		(1,762	)		(5,823	)		(5,144	)

We adopted ASU 2017-07, “Compensation—Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost,” on May 1, 2018. Refer to Note 2, "Recent Accounting Standards," in the Notes to Unaudited Condensed Consolidated Financial Statements for more information. The guidance requires that the service cost component of net pension and postretirement benefit costs be reported in the same line item as other compensation costs arising from services rendered by the pertinent employees during the period. Such amounts are reflected in Operating and Administrative Expenses on our Unaudited Condensed Consolidated Statement of Operations. The guidance requires that the other components of net benefit costs be reported separately from the service cost component and below operating income. Such amounts are reflected in Interest Income and Other on our Unaudited Condensed Consolidated Statement of Operations. We were required to retrospectively adopt this guidance.

Employer defined benefit pension plan contributions were $15.8 million and $2.8 million for the three months ended January 31, 2019 and 2018, respectively, and $22.9 million and $8.4 million for the nine months ended January 31, 2019 and 2018, respectively. Included in our defined benefit pension contributions for the three and nine months ended January 31, 2019 was a discretionary contribution of $10.0 million to the U.S. Employees' Retirement Plan of John Wiley & Sons, Inc.

The expense for employer defined contribution plans were approximately $2.6 million and $3.4 million for the three months ended January 31, 2019 and 2018, respectively, and $9.9 million and $11.3 million for the nine months ended January 31, 2019 and 2018, respectively.