PR agency profitability inched up to 16.2% last year, a marginal climb from 2013 but still below pre-recession levels of nearly 20%, according to an annual survey by Gould+Partners.

The largest firms in the survey of 104 agencies, those with revenus of $25M+, saw profitability plunge from 17.9% in 2013 to 15.8% last year.

G+P managing partner Rick Gould said declines in operating profits are completely attributable to increases in labor costs without a corresponding boost in fees.

He said only about a dozen firms consistently meet or exceed model performance targets through slow-downs and recessions due to an ability to hold salaries to under 40% of net revenues. Total labor cost should be about 50% and operating expenses.

After strong increases in 2011-12 to 18.8%, the profitability of PR firms slipped to 15.8% in 2013. Gould said firms in the $10-$25M range were the most profitable, but declined from 18.6% in 2013 to 17% last year. Smaller firms (up to $3M, and $3M-$10M) posted increases to 16.6% and 16.1%, respectively.

Gould is slated to release full results in August.