Investment income was $721,000 and $684,000 in the 2022 and 2021 thirteen-week periods, respectively.
Other operating costs increased $3,499,000 in the 2022 thirteen-week period compared to the 2021 thirteen-week period. The increase in other operating costs compared to the prior year was primarily due to increased trailing equipment maintenance costs as a result of (i) increased labor and parts costs as the Company retained older equipment to support current business levels; and (ii) an increased average trailer fleet size during the 2022 thirteen-week period, an increased provision for contractor bad debt and the impact of the resumption of large
in-person
events for the Company’s BCO Independent Contractors and independent commission sales agents.
Insurance and claims increased $9,263,000 in the 2022 thirteen-week period compared to the 2021 thirteen-week period. The increase in insurance and claims expense compared to the prior year was primarily due to the impact of net unfavorable development of prior years’ claims in the 2022 thirteen-week period, as well as increased severity of current year trucking claims during the 2022 period and an increase in insurance premiums, primarily for commercial auto and excess liability coverage. During the 2022 and 2021 thirteen-week periods, insurance and claims costs included $4,273,000 of net unfavorable and $292,000 of net favorable adjustments to prior years’ claims estimates, respectively.
Selling, general and administrative costs increased $7,305,000 in the 2022 thirteen-week period compared to the 2021 thirteen-week period. The increase in selling, general and administrative costs compared to prior year was attributable to increased wages and employee benefit costs, an increased provision for customer bad debt and an increased provision for incentive compensation, partially offset by decreased stock-based compensation expense. Included in selling, general and administrative costs was stock-based compensation expense of $1,995,000 and $4,029,000 for the 2022 and 2021 thirteen-week periods, respectively, and incentive compensation expense of $5,199,000 and $4,289,000 for the 2022 and 2021 thirteen-week periods, respectively.
Depreciation and amortization increased $1,656,000 in the 2022 thirteen-week period compared to the 2021 thirteen-week period. The increase in depreciation and amortization expenses was primarily due to increased depreciation on information technology assets.
Interest and debt expense in the 2022 thirteen-week period increased $81,000 compared to the 2021 thirteen-week period. The increase in interest and debt expense was primarily attributable to increased average borrowings on the Company’s revolving credit facility during the 2022 period, as the Company had no borrowings during the 2021 period.
The provisions for income taxes for the 2022 and 2021 thirteen-week periods were each based on an estimated annual effective income tax rate of 24.5% and 24.4%, respectively, adjusted for discrete events, such as benefits resulting from stock-based awards. The estimated annual effective income tax rate was higher than the statutory federal income tax rate of 21% in both periods primarily attributable to state taxes and nondeductible executive compensation. The effective income tax rate for the 2022 thirteen-week period was 22.8%, which was lower than the estimated annual effective income tax rate of 24.5%, primarily attributable to excess tax benefits realized on stock-based awards. The effective income tax rate for the 2021 thirteen-week period of 24.4% was equal to the estimated annual effective income tax rate during the 2021 period.
Net income was $124,839,000, or $3.34 per diluted share, in the 2022 thirteen-week period. Net income was $77,240,000, or $2.01 per diluted share, in the 2021 thirteen-week period.
CAPITAL RESOURCES AND LIQUIDITY
Working capital and the ratio of current assets to current liabilities were $588,247,000 and 1.6 to 1, respectively, at March 26, 2022, compared with $512,917,000 and 1.5 to 1, respectively, at December 25, 2021. Landstar has historically operated with current ratios within the range of 1.5 to 1 to 2.0 to 1. Cash provided by operating activities was $94,965,000 in the 2022 thirteen-week period compared with $69,891,000 in the 2021 thirteen-week period. The increase in cash flow provided by operating activities for fiscal year 2021 was primarily attributable to increased net income, partially offset by the 53% increase in revenue year-over-year, which increased net receivables, defined as accounts receivable less accounts payable.
The Company declared and paid $0.25 per share, or $9,324,000 in the aggregate, in cash dividends during the thirteen-week period ended March 26, 2022 and, during such period, also paid $75,387,000 of dividends payable which were declared during fiscal year 2021 and included in current liabilities in the consolidated balance sheet at December 25, 2021. The Company declared and paid $0.21 per share, or $8,067,000 in the aggregate, in cash dividends during the thirteen-week period ended March 27, 2021 and, during such period,