The highest CEO-to-worker pay ratio in the Philadelphia region last year belonged to Burlington Stores Inc., where the chief executive made 763 times more than the middle-of-the-pack employee.

That was no surprise to compensation experts, especially given the retailer's large number of part-time workers.

"The biggest flags for why a company would have a high pay ratio," said Thomas Langle, a compensation consultant at Mercer, "are one, having a large part-time or temporary workforce, and two, having a large overseas workforce in low cost-of-living countries."

That dynamic is evident in an Inquirer review of pay ratios at the 51 publicly traded companies in the Philadelphia region that have filed their first proxy statements with the ratios, which compare annual compensation of a company's chief executive with that of the median employee (half made more, half made less) anywhere in the world.

Burlington's CEO, Thomas A. Kingsbury, was paid $8.9 million, compared with $11,662 for the median worker. Ranking just behind was another retailer, Five Below Inc., where the ratio was 626.

Urban Outfitters Inc.'s president is paid in a similar range, but founding CEO Richard A. Hayne gets a $1 annual salary. Some retailers nationally had ratios that ran into the thousands.

Another five of the Philadelphia-area companies with the 10 highest ratios have most of their workers overseas, led by Vishay Intertechnology Inc. The Malvern electronic components maker said that 91 percent of its 23,000 employees work outside the United States. Vishay's ratio was 361, the fifth-highest in the region.

The ratios were born of a populist impulse a decade ago during the financial crisis to highlight what critics saw as outrageous executive pay. Despite the limits on the company-to-company comparability, it's good to have them, said Brandon Rees, deputy director of corporations and capital markets at the AFL-CIO.

The labor group has long published its own ratio that compares average annual pay for CEOs of S&P 500 stock index companies with the average pay of production and nonsupervisory workers. That overall ratio soared to 347 in 2016 from 42 in 1980, Rees said.

"Pay ratios matter because workers look to their CEO's pay and read into it the company's commitment to either a collaborative, egalitarian approach to compensation or a hierarchical, winner-take-all system," Rees said.

The 2010 Dodd-Frank Act required the disclosure, but the rule did not go into effect until fiscal years starting on or after Jan. 1, 2017. That means some major Philadelphia-area companies, including AmerisourceBergen Corp., Campbell Soup Co., and Toll Bros. Inc., which have fiscal years that end later in the year, have not yet filed proxy statements that include the disclosure.

The final rule for the ratio, adopted by the U.S. Securities and Exchange Commission in 2015, calls for companies to consider all employees when calculating the median, wherever they work in the world, whether they are full time, part time, seasonal, temporary, or on call, though they can exclude employees in countries where they have a small workforce.

Companies are allowed to annualize the pay of peoples who start partway through the year, and they have a great deal of flexibility in what they count toward employee compensation when calculating the median. Some show high medians for workers, for example, because they include pension gains.

The variability means that every company warns against comparing its ratio to those of others.

The employee picked to represent the median for this year's ratio can be used for two more years, as long as there are no major changes in that person's job or in the company.

Some firms described that employee. EPAM Systems Inc., a computer services firm based in Newtown, said its median was represented by a salaried employee in Russia.

Companies also can provide more disclosure. Comcast Corp., for example, explained that about 20 percent of its 172,000-strong workforce, or 34,400 people, "consisted of part-time, seasonal, or temporary employees, including in our theme park, entertainment production, and arena management businesses."

Excluding all those non-full-timers, the median Comcast employee certainly would have had a higher income than the $71,006 Comcast reported. CEO Brian L. Roberts' total compensation was $32.5 million, resulting in a ratio of 458, the fourth-highest in the region. Stephen B. Burke, CEO of Comcast's NBCUniversal, made more than his boss, with $46.5 million in total compensation. That works out to a ratio of 655.

Companies had the option of presenting alternative scenarios, but few chose to. One that did was Unisys Corp., of Blue Bell, which had a ratio of 248 under the SEC rules, but said that 75 percent of its 20,539 employees worked in relatively low-paying countries. Limiting the calculation to employees in the U.S., where the median is $85,201, compared with $30,381 overall, would result in a ratio of 88, Unisys said.

The most valuable part of the disclosure to one compensation expert is the median employee pay. "This is a data point that we think is going to be of benefit to companies," said Steve Seelig, executive compensation Counsel at Willis Towers Watson in Arlington, Va. It will help them understand whether "they are getting the best value from their workforce based on the dollars they are paying," he said.

Mary J. Mullany, a Ballard Spahr LLP partner, pointed out another aspect of the disclosure of median employee pay.

"Can you imaging being an HR director and having people knock on your door to ask, 'Why do I make less than the median? What am I, chopped liver?'"

The topic has not come up at DNB Financial Corp., said Jonathan T. McGrain, senior vice president and director of sales and marketing at the Downingtown bank.

Aside from Urban Outfitters, DNB's ratio of 10 was the lowest in the region.

McGrain said the low ratio is "probably reflective of our sense of stewardship as a community bank," McGrain said. "In addition to our customers and shareholders, we want our employees to feel that they're a valued constituency, so I think in part the ratio is reflective of that."