The Empire Center’s SeeThroughNY.net offers a new trove of payroll data on the city and public-authority governments.

An analysis of the data shows how top-heavy New York City’s public-sector payroll is compared to at least one other relevant downstate state-run public entity, the Metropolitan Transportation Authority. That is, a relatively few people, mostly educators, consume a huge amount of the taxpayer dollars spent at the New York City government.

In New York City, the 20,043 municipal employees who earn six figures a year in straight salary — no, that is not a typo, and no, it doesn’t include pension and health benefits or overtime — make up approximately 7 percent of the city’s full-time equivalent workforce.

But these same 20,043 people consume 22 percent of the city’s salary and wages budget, not including overtime.

By contrast, at the Metropolitan Transportation Authority — a better comparison than New York State, since the MTA’s employees also live in the expensive downstate region — 2.8 percent of the workforce, or a few less than 2,000 people, earn more than $100K annually in straight salary.*

This highly paid 2.8 percent of the MTA workforce consumes 5.8 percent of the MTA’s payroll budget (also not including overtime).

Unfortunately for city taxpayers, a good deal of New York City’s six-figure earners are union workers in the department of education, meaning their salaries are contractually guaranteed and can’t be cut back suddenly.

To wit: the city’s department of education — not including well-paid administrative workers like Chancellor Joel Klein — employs 13,157 six-figure workers, mostly teachers and principals, who consume $1.42 billion annually.

The MTA has more short-term flexibility for budget cuts in that it has more well-paid employees, percentage-wise, who don’t work under master contracts like the city’s teachers and principals do. (The city had that flexibility; it freely gave it away by signing generous contracts.)

But even with this flexibility — which it should make greater use of — the MTA can’t wring the bulk of the payroll savings it needs at the top. The money just isn’t being spent there.

The MTA thus needs to get the savings from better flexibility in its own union contracts that govern the wages of the bulk of its workers. Plus, it needs to wring even bigger savings from union pensions and health benefits.

This new data, then, adds to the new mystery of why the MTA decided this week to shift responsibility for negotiating its largest union contract, held with the city’s Transport Workers Union, to a state panel of arbitrators.