According to its survey of more than 1,300 U.S. companies, base pay increases for salaried exempt workers were 2.8 percent in 2012, up marginally from 2.7 percent in 2011, and pay increases are expected to rise slightly in 2013, Aon Hewitt says. For executives, salaried exempt and salaried nonexempt workers, the consulting company projects base pay increases of 3.0 percent in 2013.

According to Aon Hewitt's report, employers continue to offer variable pay, or performance-based awards that must be re-earned each year, as a primary way to drive performance and increase engagement while minimizing their fixed costs. In 2012, 90 percent of companies offered at least one variable pay program, in line with 2011.

Overall spending on variable pay as a percentage of payroll continues to rise steadily for salaried exempt workers, Aon Hewitt says. In 2012, companies spent 12.0 percent on variable pay, compared to 11.6 percent in 2011. Spending is expected to rise slightly to 12.1 percent in 2013.

Nonunion hourly workers saw the biggest jump in variable pay in 2012. As a percentage of payroll, employers spent 6.0 percent on variable pay rewards for nonunion hourly workers in 2012, compared to 5.2 percent in 2011. However, spending is expected to fall slightly to 5.6 percent in 2013 for this group, Aon Hewitt says.