concurring in part and dissenting in part:
There is an inherent hazard in the process by which our courts flesh out the meaning of a statute. Over time, judges adding another link to the precedential chain may become so intent on exploring the implications of the last preceding case *288that they lose sight of the statute itself and end up frustrating its purpose. Such is the case with the decision we issue today.
After reviewing the exemption’s legislative history, we observed, in National Parks, that the exemption covered two categories of private commercial information in the government’s possession: that which is voluntarily provided and that which is exacted by statute or regulation. 498 F.2d at 769. We concluded that Congress had
a twofold justification for the exemption of commercial material: (1) encouraging cooperation by those who are not obliged to provide information to the government and (2) protecting the rights of those who must.
Id. The INPO reports clearly fall within the first category. Yet rather than apply exemption 4 in a manner consistent with the congressional purpose of encouraging the private sector to cooperate with government, we place it on notice that anyone who voluntarily provides the government with confidential information does so at significant risk.
The majority and I agree that the reports are shielded from disclosure if, as the agency contends, the information they contain is confidential within the meaning of exemption 4. We part company on how that information is to be categorized. In National Parks this court established a test for determining this key element of section 552(b)(4):
[A] commercial or financial matter is “confidential” for purposes of the exemption if disclosure of the information is likely to have either of the following effects: (1) to impair the Government’s ability to obtain necessary information in the future; or (2) to cause substantial harm to the competitive position of the person from whom the information was obtained.
Id. at 770. Given the court’s finding as to the exemption’s purposes, I read the first element of the test (in the case of information a person is not required to provide) to refer to the effect of disclosure on an agency's future ability to obtain necessary information on a voluntary basis. The court, however, now rewrites the test to provide that commercial information will be deemed “confidential” only if its disclosure would impair the government’s ability to compel the production of like information in the future from whatever source, and it claims to do so on the authority of National Parks and Washington Post. Maj. op. at 284 n. 26.
Neither case supports so radical a change. National Parks and Washington Post deal with information third parties have been required to provide government agencies. In each case the court must decide whether public disclosure will impair the accuracy of future information received from those same parties even though its production is mandatory. Nowhere is it suggested that in applying the exemption, an agency’s ability to obtain information is to be measured by what it might be able to compel from other sources were it to unleash the statutory powers at its disposal.
Taken alone, the phrase “ability to obtain” is capable of a broad range of interpretations. Exemption 4, however, must be applied within the scope of its statutory context and purpose. FOIA is a disclosure statute. It deals with information currently in an agency’s possession, and with the nature and sources of that information. It does not require that the agency determine how it might coerce the production of information it presently receives to its satisfaction through cooperative means. In short, there is no basis in the statute for the ruling we announce today; a ruling that is unwarranted by circuit precedent, at odds with precedent elsewhere,* and subversive of one of Congress’ prime objectives, namely, to “encourag[e] cooperation by those who are not obliged to provide information to the government.” National Parks, 498 F.2d at 769. In fact, it is hard to conceive of a rule more likely to discourage such cooperation, as citizens are now forewarned that confidential information they voluntarily provide may be disclosed whenever a court concludes that the agency has *289the power to compel the production of similar information from any other source.
My concern over today’s decision goes beyond its emasculation of exemption 4. I fear we may be opening a vast new field for future litigation. What are the limits of a presumption that any information voluntarily provided under a promise of confidentiality is subject to FOIA disclosure if the production of similar information could be compelled? Would not such a standard force courts to adjudicate a host of hypothetical claims: Does the statutory power exist to compel disclosure? If the power exists, does it apply to the particular matter being sought; and, if it does apply, would program efficiency be impaired? — all this simply to determine whether the material is exempt from FOIA absent an invocation of these hypothetical powers. Maj. op. at 287. Given the sweeping reach of FOIA, are we not sanctioning a wholly novel form of suit?
As I concur in the court’s adoption of the holding in 9 to 5 Organization, Maj. op. at 286,1 agree that on remand, the NRC may base its claim of exemption on the alternative ground of impairment of the efficient and effective performance of its regulatory responsibilities.
Cf. General Electric Co. v. NRC, 750 F.2d 1394, 1398 (7th Cir.1984) (information exempt "if disclosure would ... make it difficult for the agency to induce people to submit similar information to it in the future” (citing National Parks )).