Even as its donor base grows considerably, the National Republican Congressional Committee is filing disclosure records with less and less information about the people who are giving.

Through April, the committee failed to identify an occupation for more than 73 percent of the nearly 38,000 individual contributors listed in its month-to-month reports. Even a greater percentage of the givers were listed without naming an employer.

The degree of nondisclosure by the NRCC has made it virtually impossible to tease out patterns among the committee’s givers this cycle. And it has raised suspicions among campaign finance watchdogs about whether the NRCC may be capriciously — or even willfully — flouting the law, which requires the committee to try to obtain basic details about its donors.

“This tells me they’re not putting a high priority on it — that they are not indicating to contributors that this is information that they really want from them,” said Larry Noble, executive director of the Center for Responsive Politics.

While political committees must ask givers to reveal their employers and occupations, they are not obligated to succeed in getting answers. Under the law, the committees need only demonstrate that they have used “best efforts” — often through follow-up letters or phone calls — to obtain the information.

It’s for that reason that committees are only very rarely fined by the Federal Election Commission.

The NRCC figures stand in sharp contrast to those of the committee’s partisan counterpart, the Democratic Congressional Campaign Committee, which listed an occupation for roughly 80 percent of its contributors during the same four-month period, according to PoliticalMoneyLine.com, an independent campaign finance database that has crunched the numbers.

The contributor information for the National Republican Senatorial Committee or the Democratic Senatorial Campaign Committee cannot be readily compiled because neither files electronically.

NRCC spokesman Carl Forti said he cannot explain why the committee has lagged in collecting basic information from its contributors this cycle. But he insisted the NRCC was trying to fill in the blanks.

“We ask [for the details], people don’t give it, we send a follow-up letter requesting the information,” Forti said.

Forti claimed the NRCC, which is chaired by Rep. Tom Reynolds (N.Y.), has sent more than 20,000 such letters already this year. He refused to turn over any copies of direct-mail solicitations that would indicate how information is requested from donors.

By way of contrast with the GOP committee, DCCC spokesman Greg Speed said that finance staffers follow up with “at least” a phone call in instances where no occupation or employer is provided by the contributor.

“The law is very clear. You’ve gotta make best efforts,” Speed said. “We obviously do a better job of it than the NRCC does.”

To be sure, the DCCC’s relatively small donor base makes the phone approach less burdensome than it would be for the NRCC. The DCCC listed only 1,000 individual contributors in the first four months of 2003 — almost 38 times fewer than the opposition.

The major party committees have traditionally fared more poorly than Congressional candidates in collecting information about their contributors.

Still, the NRCC numbers reflect a considerable degree of erosion over previous years in which the committee established something of a standard for non-transparency.

Fewer than 50 percent of the more than 166,000 individuals who gave money to the NRCC during the 2002 cycle failed to provide the committee with details about their occupations or employers, compared with 20 percent at the DCCC. (The NRCC and DCCC fared somewhat worse under the methodology used by the CRP, Noble’s group.)

The employment data collected by the political committees can in some instances be the only way to determine whether a particular contributor even exists. Without such information, it would be virtually impossible to tell, for instance, whether there actually is a donor named John Smith in New York City, or whether there is only an address from which a “John Smith” writes checks.

Noble, for one, suggested the extent to which committees fail to collect basic data from their contributors reflects the fact that they don’t want the information; they would prefer that media outlets and watchdog groups do not establish patterns among the givers.

At the same time, the FEC has little leverage in the matter if committees can avoid penalties by showing they followed up with those who did not initially provide details.

“History has shown that if political committees want to get this information, they can get it,” Noble said, citing as an example instances where candidates have indicated they will not deposit checks that arrive without details about the contributors.

“It just depends on how interested they are in trying to get it.”

FEC spokesman Bob Biersak said the commission has no precise threshold it uses to determine when it should look into the disclosure provided by a political committee. He indicated that in the vast majority of instances committees have been able to show the FEC that they have labored to get the requested information.

Reflecting on the NRCC’s numbers this cycle, Biersak said, “Certainly at that level we would be asking them what they are doing [to get the information].”

Only twice in its history has the FEC fined political committees for not making “best efforts.” Former Rep. Jack Metcalf’s (R-Wash.) campaign was fined $7,000 for violations during the 1996 cycle. The FEC said the committee failed to provide timely responses to requests for information from the commission, and then failed to amend its financial reports on time.

In 1997, the Republican National Committee settled with the FEC for $20,000 after the committee was cited for failing to follow-up adequately with contributors who did not provide the necessary information.

During the period preceding the fine, the RNC had been challenging a 1994 decision by the commission that required committees to make stand-alone requests for additional data from contributors who had not provided it. The RNC’s practice had been to send out a second solicitation that repeated the unanswered requests made in the first.