A subway ad that appeared in 2009. (Photo courtesy of gguillaumee/Flickr)

Lamenting his ability to trim the city’s budget, Mayor Bloomberg this week assailed increases in teacher salaries. But he hasn’t always seen teachers’ salaries as a burden.

A ad campaign promoting the public schools that plastered subways in late 2008 touted increases in teacher salaries as a statistic to be proud of. “Because every child deserves a great teacher, New York City public schools have increased starting teacher salaries 43% since 2002,” read one of the posters in the Keep It Going NYC campaign.

In the last two and a half years, of course, the city’s fiscal picture has changed, and Bloomberg is now hoping to persuade the teachers union to accept steep concessions to avert layoffs. Earlier this week, he cited the increase in teacher salaries as evidence that concessions are needed. “I can tell you we have raised teacher spending in 10 years 105 percent on the Department of Education and we’ve raised it on all other city agencies an average of 28 percent, with an inflation rate of 33 percent [since 2002],” he said.