Emergency responders who were killed or seriously injured in the Sept. 11, 2001, attacks each received about $1 million more than other victims of the terrorist strikes, although most of that difference was due to large donations from charities, according to a study released yesterday.

In the most comprehensive look at how government money, charitable awards and insurance payments were disbursed after the attacks, the Rand Institute for Civil Justice found that families of the dead and injured and businesses affected by the attacks received more than $38 billion in compensation.

Just over half that amount came from insurance companies, and an additional 42 percent came from state and federal governments, according to the study. More than $23 billion of the total went to businesses in Lower Manhattan and elsewhere in New York City that were displaced or shuttered by the attacks. Three-quarters of that money came from insurance claims, the study found.

The review, conducted by an arm of the Santa Monica, Calif.-based Rand Corp., provides the most definitive estimate to date of the sums given to Sept. 11 victims and their families, and it underscores the disorganized way in which those contributions were doled out.

Lloyd Dixon, a Rand senior economist and lead author of the report, said in an interview that he was surprised by the sheer size of charitable donations to the families of firefighters and other emergency responders. Rand estimates that 425 firefighters, police officers and other responders were killed during and after the attacks, and that they received about $500 million in charitable gifts alone.

"The magnitude of the charitable giving shows the chord that was struck," Dixon said. "Half a billion dollars for just over 400 people is a tremendous amount of money. . . . The question is how that translates into policies for future events."

Kenneth R. Feinberg, who headed the federal government's Sept. 11 fund, said he expects to release a final report next week on payments from that fund. The Rand study noted that many families have complained about the formulas used to disburse the awards but said there was too little data to reach definitive conclusions.

Representatives of victims organizations did not return phone calls seeking comment.

Among the findings in the 173-page report:

* Responders and their families received an average of $4.2 million from all sources, compared with $3.1 million for other victims. Nearly all the difference is attributable to charitable donations and to payments from New York's Public Safety Officers' Benefits program.

* Civilians and their families received a total of $8.7 billion in assistance, including payments from the federal government's September 11th Victim Compensation Fund. The attacks killed 2,551 non-emergency personnel and seriously injured 215, according to Rand.

* The 460 emergency responders killed or seriously injured received a total of $1.9 billion, including charitable gifts, pensions and other payments.

* About $3.5 billion was paid to people who lost their homes or jobs, to rescue personnel exposed to environmental hazards, or to others who claimed emotional injuries as a result of the attacks or rescue operations.

* No money has been awarded through lawsuits or other court actions, though civil cases are pending.

The study found that federal government actions limiting liability for airlines and airports made litigation more difficult, but the researchers warn that officials have not devised a general compensation plan for terrorist events. A federal law that protects companies against losses in a future attack is likely to be a focus of debate in Congress next year, when it is set to expire.

The report's authors argue that the government should create a system to deal with future attacks, and they noted that compensation packages varied dramatically both among Sept. 11 victims and in comparison with victims of other attacks, such as the 1995 Oklahoma City bombing.

"The benefits received by individuals and businesses affected by the 9/11 attacks were the result of a unique combination of insurance, the tort system, government programs and charity," the study's authors wrote. "There is no guarantee that a similar mix of resources will be available for the victims of a future terrorist attack."