Courts give substantial weight and deference to an administrative agency’s interpretation of an ambiguous statute[i].  The reason for this deference is that agencies make informed judgments about the issues based on their experience.

However, an administrative agency’s decision on question of law does not bind the courts[ii].  Also courts may reverse an agency on a mixed question of fact and law if the decision is erroneous[iii].  In Jones v. The Lodge at Torrey Pines Partnership, 42 Cal. 4th 1158 (Cal. 2008), the court held that although the construction of a statute by administrative agencies are entitled to great weight, the final responsibility for the interpretation of the law rests with the courts.  The courts will set aside the legal rulings of administrative agencies if they violate the constitution or a statute or contain a substantial and material error of law[iv].

Deference does not mean acquiescence[v].  When a court reviews the interpretation of statute done by administrative agency, the court looks whether Congress has directly spoken to the precise question at issue.  If the intent of Congress is clear, the agency should give effect to the unambiguously expressed intent of Congress.  If, the court determines Congress has not directly addressed the precise question at issue, the court looks whether the agency’s answer is based on a permissible construction of the statute[vi].

[i] Moncada v. Illinois Commerce Com., 212 Ill. App. 3d 1046 (Ill. App. Ct. 1st Dist. 1991)

[ii] Big Ten Conf. v. Department of Revenue, 312 Ill. App. 3d 88 (Ill. App. Ct. 1st Dist. 2000)

[iii] id

[iv] Adrian School Dist. v. Michigan Pub. Sch. Emples. Retirement Sys., 458 Mich. 326 (Mich. 1998)

[v] Presley v. Etowah County Comm’n, 502 U.S. 491 (U.S. 1992)

[vi] J.R. Simplot Co. v. Idaho State Tax Comm’n, 120 Idaho 849 (Idaho 1991)