This school year is do or die for Edison.(Knight Ridder Newspapers)

PHILADELPHIA _ With 82,000 students and 150 schools in 23 states, Edison Schools Inc. has achieved many goals, except the one that was supposed to revolutionize education: profits.

As the company approaches its 10th year in business, supporters are backing away from rosy projections about how Edison can enrich both schoolchildren and shareholders, while critics question whether the company can ever make money.

The intense scrutiny _ much of it brought on by the company's contract to run 20 Philadelphia schools, the largest-ever experiment in privatizing public education _ may mean this school year is do or die for Edison. With its stock trading at 33 cents per share, down from its 52-week high of $21.68, the New York company must make good on profits promised in its Sept. 5 conference call with investors.

Its business model is based on the premise that a private company can run a school system more efficiently than government. In this worldview, layers of bureaucrats with little incentive to manage a school district's resources effectively or improve student performance create a bloated system.

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