2011 acquisitions of Winterthur Technologie AG and the do-it-yourself and professional business of GPI Group, in addition to SG&A spending related to the 2012 acquisitions of Ceradyne, Inc., Federal Signal Technologies Group, and CodeRyte, Inc. SG&A, measured as a percent of sales, was 20.4 percent in 2012, a decrease of 0.4 percentage points when compared to 2011.

 

Research, Development and Related Expenses:

 

Research, development and related expenses (R&D) increased 4.9 percent in 2013 compared to 2012 and increased 4.1 percent in 2012 compared to 2011, as 3M continued to support its key growth initiatives, including more R&D aimed at disruptive innovation. In 2013, increases from acquired businesses that were largely not in 3M’s 2012 spending (primarily Ceradyne, Inc. and Federal Signal Technologies) were partially offset by lower pension and postretirement expense. In 2012, investments to support key growth initiatives, along with higher pension and postretirement expense, were partially offset by cost-control efforts and savings from 3M’s first-quarter 2012 voluntary early retirement incentive program. R&D, measured as a percent of sales, was 5.6 percent in 2013, compared to 5.5 percent in 2012 and 5.3 percent in 2011.

 

Operating Income:

 

3M uses operating income as one of its primary business segment performance measurement tools.

 

Operating income margins were 21.6 percent in 2013, compared to 21.7 in 2012, a decrease of 0.1 percentage points. Items that reduced operating income margins included a 0.5 percentage point impact from lower factory utilization/productivity, along with a 0.4 percentage point impact from the combination of business transformation, enabled by 3M’s global ERP implementation, along with more R&D aimed at disruptive innovation. The recently enacted medical device excise tax in the U.S., foreign currency effects, acquisition impacts, and other net impacts reduced operating income margins by 0.7 percentage points. These factors were largely offset by items that increased operating income margins, which included a 1.2 percentage point benefit from the combination of selling price increases and raw material cost decreases. Finally, lower pension/postretirement benefit costs increased operating income margins by 0.3 percentage points.

 

Operating income was 21.7 percent of sales in 2012, compared to 20.9 percent of sales in 2011, an improvement of 0.8 percentage points. The improvement was driven by a 1.6 percentage point benefit from the combination of selling price increases and raw material cost decreases. This was partially offset by increased pension/postretirement benefit costs and acquisition impacts, each of which reduced margins by 0.3 percentage points, and other net impacts, which decreased margins by 0.2 percentage points.

 

Interest Expense and Income:

  

Interest Expense: Interest expense decreased in both 2013 and 2012. The 2013 decrease was primarily due to lower interest rates. The 2012 decrease was driven by lower average international debt balances and lower interest rates on U.S. debt.

 

Interest Income: Interest income was up $2 million when comparing 2013 to 2012, as