See for example, his May 24th testimony to the City council here:
Each time, we’ve worked to minimize the impact on schools and students. Between 2008 and this school year, we have cut the central administrative budget by nearly 20-percent—more than double the reduction to school budgets. This has included a headcount reduction of 550 positions in central and field offices….
Meanwhile I did some calculations based on the DOE’s financial status reports. I looked at full-time positions on payroll, by category, in each year's May report (except for 2008, when I drew from the April report, since there was no report in May.)
But the number of full time school-based positions, including total general education, special ed instruction and school leadership, as well as categorically- funded positions, have been cut nearly three times as much. This is the period over which school budgets have been slashed to the bone.
If one doesn’t count the categorical positions that were funded primarily through the federal stimulus program, the headcount reductions at schools would be five times as large as those from central administration.
The disparities are even greater if you look further back in time.
Between 2006 and 2010, the number of full time positions at central administration has grown by 7.4%, while the number of full-time school personnel has shrunk by nearly the same percent -- 7.5%.
See also today's NY Post on how the number of DOE employees being paid $150,000 or more has mushroomed by 25% this year.