We generally hold approximately 10%-30% of these short-term funds in U.S. tax jurisdictions. The amount of funds held in U.S. tax jurisdictions can fluctuate due to the timing of receipts and payments in the ordinary course of business and due to other reasons, such as business-development activities. As part of our ongoing liquidity assessments, we regularly monitor the mix of domestic and international cash flows (both inflows and outflows). Repatriation of overseas funds can result in additional U.S. federal, state and local income tax payments. We record U.S. deferred tax liabilities for certain unremitted earnings, but when amounts earned overseas are expected to be indefinitely reinvested outside the U.S., no accrual for U.S. taxes is provided.

Accounts Receivable

We continue to monitor developments regarding government and government agency receivables in several European markets where economic conditions remain challenging and uncertain. Historically, payments from a number of these European governments and government agencies extend beyond the contractual terms of sale, and there have been no significant changes in the year-over-year trend.

We believe that our allowance for doubtful accounts is appropriate. Our assessment is based on an analysis of the following: (i) payments received to date; (ii) the consistency of payments from customers; (iii) direct and observed interactions with the governments (including court petitions) and with market participants (for example, the factoring industry); and (iv) various third-party assessments of repayment risk (for example, rating agency publications and the movement of rates for credit default swap instruments).

As of December 31, 2013, we had about $1.1 billion in aggregate gross accounts receivable from governments and/or government agencies in Spain, Italy, Greece, Portugal and Ireland where economic conditions remain challenging and uncertain. Such receivables in excess of one year from the invoice date, totaling $245 million, were as follows: $149 million in Spain; $51 million in Italy; $34 million in Greece; $10 million in Portugal; and $1 million in Ireland.

Although certain European governments and government agencies sometimes delay payments beyond the contractual terms of sale, we seek to appropriately balance repayment risk with the desire to maintain good relationships with our customers and to ensure a humanitarian approach to local patient needs.

We will continue to closely monitor repayment risk and, when necessary, we will continue to adjust our allowance for doubtful accounts.

Our assessments about the recoverability of accounts receivables can result from a complex series of judgments about future events and uncertainties and can rely heavily on estimates and assumptions. For information about the risks associated with estimates and assumptions, see Notes to Consolidated Financial Statements––Note 1C. Basis of Presentation and Significant Accounting Policies: Estimates and Assumptions.

Credit Ratings

Two major corporate debt-rating organizations, Moody’s and S&P, assign ratings to our short-term and long-term debt. A security rating is not a recommendation to