Some officials are running two or more agencies. That would be a suboptimal situation in any city. In New York, where some agencies have budgets larger than the total spending of many states, it’s a management approach worth questioning.

Lorraine Grillo, for instance, is running both the School Construction Authority, with a $205 million budget, and the Department of Design and Construction, after that agency’s former commissioner resigned in 2017 amid a half-billion dollars in cost overruns on the city’s Sandy recovery program.

Then there’s Kathryn Garcia, the city’s sanitation commissioner, who was tapped in February to serve as interim chief executive of the Housing Authority after it was discovered that the agency mishandled lead inspections, allowing hundreds of children to be exposed to lead paint. The first deputy sanitation commissioner, Steven Costas, is leading that department as acting commissioner until Ms. Garcia returns full time. The Sanitation Department has a budget of $1.7 billion. The Housing Authority’s annual operating budget is $3.5 billion .

In one especially odd episode, Joseph Esposito, commissioner of the city’s Office of Emergency Management, continues to lead the agency months after he was abruptly fired in the wake of criticism over the city’s handling of a snowstorm. A de Blasio spokesman told Politico, which first reported the extent of the vacancies, that there was a continuing search for Mr. Esposito’s replacement.

Maybe that’ll happen soon, if Mr. de Blasio can carve out the time.

The mayor, who has two and a half years left in his second term , has recently focused his attentions elsewhere. Yet, especially if he’ll be on the campaign trail, filling these positions is the least Mr. de Blasio can do to make sure the city that elected him gets the services it deserves.

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