As Mayor Mitch Landrieu and other officials continue to call for a bigger Police Department, New Orleans Inspector General Ed Quatrevaux is asking the city to stop for a moment and ask whether spending more money on police will actually make the city safer.

Quatrevaux said in a report issued Wednesday that a vague NOPD budget coupled with inadequate performance measures leave both the mayor and the public in the dark about how effective hiring hundreds of new officers would be.

Police Superintendent Michael Harrison shot back that he “strongly” disagrees with the notion that department data are unreliable.

Quatrevaux’s 56-page report attempts to provide an overview of how the NOPD is funded, how much it spends and where the money goes.

The city consistently expends about a quarter of its roughly $500 million annual budget on the NOPD, but Quatreveux said very little is known about how that money is spent beyond broad budget outlines.

Although training officers is a top priority for the department and a major focus of the 2012 federal consent decree the city signed with the U.S. Department of Justice, Quatreveux said the NOPD could not break down how much money it spends on training, including the crucial question of how much it will cost to train new officers on a per-person basis.

Quatreveux also claimed that “critical flaws” in NOPD data on police response times, citizen complaints and reported crime rates undermine any attempt to answer the question of how much bang for its buck the NOPD gets.

Over the past two years, other reports faulted the department for how it reports serious crimes, how it labels rapes and how it classifies robberies.

“New Orleans may well face unprecedented increases in the cost of law enforcement from rising pension costs and appeals for higher salaries, as well as the planned increase in the number of officers,” the IG’s report concludes. “The bar will have to be raised on the information NOPD provides.”

But Harrison and City Hall both argued in their official responses to Quatreveux’s report that under Landrieu the city has taken serious strides in making its crime data more reliable and accessible.

Chief Administrative Officer Andy Kopplin pointed to the department’s public Comstat meetings, an open data platform recently praised by the nonprofit Sunlight Foundation, as well as ResultsNOLA performance reports, which track crime measures, clearance rates, civilian complaints and recruiting numbers.

Harrison said he continues to dispute a previous IG report about police response times. He argued there was “no apparent trend or commonality” to suggest that the 8 percent of NOPD calls where no response time was logged might have raised the department’s overall average.

Harrison also charged that the IG has drawn “sweeping conclusions” about crime underreporting from “small subsets” of data.

“No data that is produced by human beings will ever be completely infallible,” Harrison said. “However, I believe that we have put in place a number of quality control measures in the last several years that enhance the quality and integrity of NOPD’s data.”