is our former Animal Health business. For further details on Zoetis-related transactions, see Notes to Consolidated Financial Statements—Note 2D. Acquisitions, Licensing Agreements, Collaborative Arrangements, Divestitures, and Equity-Method Investments: Divestitures. For further details on the transfer of certain product rights, see Notes to Consolidated Financial Statements—Note 2E. Acquisitions, Licensing Agreements, Collaborative Arrangements, Divestitures, and Equity-Method Investments: Equity-Method Investments.

ANALYSIS OF FINANCIAL CONDITION, LIQUIDITY AND CAPITAL RESOURCES

We rely largely on operating cash flows, short-term investments, short-term commercial paper borrowings and long-term debt to provide for our liquidity requirements. Due to our significant operating cash flows as well as our financial assets, access to capital markets and available lines of credit and revolving credit agreements, we believe that we have, and will maintain, the ability to meet our liquidity needs for the foreseeable future, which include:

• the working capital requirements of our operations, including our research and development activities;

• investments in our business;

• dividend payments and potential increases in the dividend rate;

• share repurchases;

• the cash requirements associated with our cost-reduction/productivity initiatives;

• paying down outstanding debt;

• contributions to our pension and postretirement plans; and

• business-development activities.

For additional information about our share-purchase plans, see the “Share-Purchase Plans” section of this Financial Review.

Our long-term debt is rated high-quality by both Standard & Poor’s (S&P) and Moody’s Investors Service (Moody's). See the “Credit Ratings” section below. As market conditions change, we continue to monitor our liquidity position. We have taken and will continue to take a conservative approach to our financial investments. Both short-term and long-term investments consist primarily of high-quality, highly liquid, well-diversified and available-for-sale debt securities.

    Selected Measures of Liquidity and Capital Resources

On May 15, 2014, we completed a public offering of $4.5 billion aggregate principal amount of senior unsecured notes (see Notes to

Consolidated Financial Statements––Note 7D. Financial Instruments: Long-Term Debt).

On June 3, 2013, we completed a public offering of $4.0 billion aggregate principal amount of senior unsecured notes. In addition, we repaid at maturity our 3.625% senior unsecured notes that were due June 2013, which had a balance of $2.4 billion at December 31, 2012, and, in December 2013, we redeemed the aggregate principal amount of $1.8 billion of our 5.50% senior unsecured notes that were due in February 2014.

Subsequent Event

On February 5, 2015, we announced that we have entered into a definitive merger agreement under which we agreed to acquire Hospira, the world’s leading provider of injectable drugs and infusion technologies and a global leader in biosimilars, for $90 per share in cash, for a total enterprise value of approximately $17 billion. We expect to finance the transaction through a combination of