Williams ruled out a possible run on election night, but Butkovitz said he was still weighing the possibility.
"We are gauging support and meeting with people," he said after his inauguration. "It hasn't gotten to the point where we would abruptly resign."
Butkovitz seemed to preview a political strategy that worked well for another recent candidate - Bill de Blasio, who was elected mayor of New York City after campaigning to tackle economic inequality.
Entering his third term as controller, Butkovitz called "for a shift in the terms of the debate" on jobs and the economy.
"We are truly becoming two cities: one highly skilled and high-wage," he said, "the other stuck in a trap of unemployment and underemployment."
He spoke at length about the city's financially troubled schools, and said economic growth strategies needed to focus on more than reforming the city's tax structure, which is heavily weighted against businesses.
He likened the state's Keystone Opportunity Zones, which offer tax breaks to employers who promise to hire or expand, to "Cayman Islands-like tax-free zones" that have had "minimal long-term impact on job creation."
On several occasions, he referenced City Council President Darrell L. Clarke's Jobs Commission and Councilman Bobby Henon's Manufacturing Task Force as "large steps in the right direction."
"If we don't fix our schools and put our people to work, this 'second city' will only become larger and continue to impede our chance for success," he said.
Butkovitz said he would lead an effort to encourage the city's colleges, hospitals, and other "anchor" institutions to support a program to "make it and buy it in Philly."
His office is planning to release a study this month showing that the major employers are "exporting" $2 billion a year to buy the goods and services they need.
Williams, entering his second term as district attorney, mostly looked back on changes he championed in his first four years, when he said the criminal justice system went from "an example of utter dysfunction" to "a model for other jurisdictions to replicate."
"I said back then that we'd be smart on crime, not just tough," he said. "It was a new paradigm of what it meant to be a prosecutor, and we've done just that."
Williams said an "unprecedented" 43 percent of misdemeanor cases are now resolved through diversionary programs, giving first-time offenders "the chance to redeem themselves."
Williams was introduced by State Sen. Anthony Hardy Williams (D., Phila.), who is no relation. The legislator, who is considering a run for mayor, spoke of the racial injustice, backlash, and corruption that have marred the city's history. He praised the district attorney for his "commitment to change" and called him "one of our brightest stars."
"People have to believe the system is fair and that it works the same for everyone," the district attorney said. "We are much closer to that goal than we were four years ago."
In a nod to his effort to prosecute Msgr. William J. Lynn, whose child-endangerment conviction was recently overturned, Seth Williams said he would "continue to champion the victims of child sexual abuse."
He added that his office would "hold accountable the offenders and the institutions that protect them."
Archbishop Charles J. Chaput had been scheduled to give the invocation at the inauguration, but was stuck traveling back from the Midwest because of bad weather and could not attend.
Williams last week sharply criticized Chaput for the archdiocese's putting up the $25,000 needed to secure the bail to free Lynn.