2012, a decrease of approximately $2.2 billion. Factors which reduced working capital on a combined basis by $2.4 billion included decreases in cash, cash equivalents, and current marketable securities, along with increases in the current portion of long term debt (which is a component of short-term borrowings and current portion of long-term debt) and increases in other current liabilities, largely related to the dividend declared in December 2013 that will not be paid until March 2014 (discussed in Note 5). This was partially offset by increases in accounts receivable of approximately $0.2 billion.

 

The Company uses various working capital measures that place emphasis and focus on certain working capital assets and liabilities. These measures are not defined under U.S. generally accepted accounting principles and may not be computed the same as similarly titled measures used by other companies. One of the primary working capital measures 3M uses is a combined index, which includes accounts receivable, inventories and accounts payable. This combined index (defined as quarterly net sales — fourth quarter at year-end — multiplied by four, divided by ending net accounts receivable plus inventories less accounts payable) was 4.8 at both December 31, 2013 and December 31, 2012. Receivables increased $192 million, or 4.7 percent, compared with December 31, 2012, driven by a year-on-year increase in December sales, partially offset by currency translation, which decreased accounts receivable by $135 million. Inventories increased $27 million, or 1 percent, compared with December 31, 2012, with the increases primarily attributable to an increase in demand in the fourth-quarter of 2013, partially offset by currency translation, which decreased inventories by $75 million. Accounts payable increased $37 million compared with December 31, 2012, primarily related to changes in business activity, which were partially offset by a $29 million decrease due to currency translation.

 

Cash flows from operating, investing and financing activities are provided in the tables that follow. Individual amounts in the Consolidated Statement of Cash Flows exclude the effects of acquisitions, divestitures and exchange rate impacts on cash and cash equivalents, which are presented separately in the cash flows. Thus, the amounts presented in the following operating, investing and financing activities tables reflect changes in balances from period to period adjusted for these effects.

 

Cash Flows from Operating Activities:

  

Cash flows from operating activities can fluctuate significantly from period to period, as pension funding decisions, tax timing differences and other items can significantly impact cash flows.

 

In 2013, cash flows provided by operating activities increased $517 million compared to 2012. Operating cash flows benefited year-on-year from $664 million of lower pension and postretirement plans contributions and increases in net income including noncontrolling interest, which were partially offset by higher year-on-year working capital requirements. The combination of accounts receivable, inventories and accounts payable increased working