industry, they have not as yet resulted in fully restoring our margins to historical levels. Continuing increases in input costs and overall high inflation may not allow us to fully restore our margins to these historical levels. Although the Company continues to monitor these higher input costs and price increases in the industry, we are mindful of the effects and limits of passing on all of the above discussed higher input costs to our customers as well as the final consumers of our products.
Our supply chain improved in first quarter 2023 after a very challenging 2022. We are, however, continuing our focus on the supply chain and possible delays and disruptions which could result in the temporary shut-down of one or more manufacturing lines resulting in lost sales and profits in 2023. Labor shortages at some of our manufacturing plant locations continue to contribute to production and sales limitations of some products in 2023, just as it did in 2022. We did expand our work shifts and overtime in first quarter 2023 in order to increase production and mitigate some of the adverse effects of this labor shortage. Nonetheless, we believe that we can meet substantially all of our labor and work shift needs in 2023, however, the tight labor market has created many more challenges than in the past.
Although unfavorable foreign exchange did have some adverse effects on first quarter 2023 net earnings, higher interest income from the Company’s marketable securities investments did contribute to the increase in net earnings in first quarter 2023 compared to first quarter 2022. The Company’s effective income tax rates were 23.8% and 24.0% in first quarter 2023 and 2022, respectively. Earnings per share did benefit from stock purchases in the open market resulting in fewer shares outstanding in first quarter 2023.
We are focused on the longer term and therefore are continuing to make investments in plant manufacturing operations to meet new consumer and customer product demands, achieve product quality improvements, expand capacity in certain product lines, and increase operational efficiencies in order to provide genuine value to consumers. Although the Covid-19 pandemic appears to have significantly subsided, it has been an unprecedented event and therefore the Company is unable to determine any related effects on its sales and net earnings for 2023 and beyond.”
Safe Harbor Statement
This release contains forward-looking statements that are based largely on the Company’s current expectations and are made pursuant to the safe harbor provision of the Private Securities Litigation Reform Act of 1995. Forward-looking statements can be identified by the use of words such as “anticipated,” “believe,” “expect,” “intend,” “estimate,” “project,” “plan” and other words of similar meaning in connection with a discussion of future operating or financial performance and are subject to certain factors, risks, trends and uncertainties that could cause actual results and achievements to differ materially from those expressed in the forward-looking statements. Such factors, risks, trends and uncertainties, which in some instances are beyond the Company’s control, include the overall competitive environment in the Company’s industry, supply chain disruptions, labor shortages, union labor contract negotiation impasses and stoppages, and changes in assumptions, judgments and risk factors discussed in our Annual Report on Form 10-K for the year ended December 31, 2022.
The risk factors referred to above, including the effects of the Covid-19 pandemic and related variants, are believed to be significant factors, but not necessarily all of the significant factors that could cause actual results to differ from those expressed in any forward-looking statement. Readers are cautioned not to place undue reliance on such forward-looking statements, which are made only as of the date of this report. The Company undertakes no obligation to update such forward-looking statements.
