In the Philippine legal landscape, administrative agencies are often described as the "Fourth Branch of Government." While the Constitution traditionally divides power among the Legislative, Executive, and Judicial branches, the complexity of modern society necessitates specialized bodies to manage intricate social and economic issues. These agencies—ranging from the Securities and Exchange Commission (SEC) to the National Labor Relations Commission (NLRC)—operate under a delegated authority that blends functions from all three traditional branches.

The following is an exposition of the powers vested in these agencies under Philippine Administrative Law.

I. The Source and Nature of Power

Administrative agencies possess no inherent powers. Their authority is entirely derivative, stemming from:

The Constitution: Some agencies (e.g., Constitutional Commissions like the COMELEC) derive power directly from the fundamental law.
Statutes: Most agencies are created by an "Enabling Act" or Charter passed by Congress, which defines the scope and limits of their jurisdiction.

The fundamental principle governing these powers is the Doctrine of Non-Delegation of Powers, which states that what has been delegated cannot be further delegated (potestas delegata non delegari potest). However, delegation is valid if it meets two tests:

The Completeness Test: The law must be complete in all its terms and conditions when it leaves the legislature.
The Sufficient Standard Test: The law must map out the boundaries of the delegate's authority by providing a standard to guide the agency.

II. Quasi-Legislative (Rule-Making) Power

This is the power to make rules and regulations which have the force and effect of law. It is "quasi" (as if) legislative because while agencies are part of the Executive, they perform a function traditionally reserved for Congress.

Types of Administrative Rules:

Supplementary Rules: These "fill in the details" of a broad statute.
Interpretative Rules: These provide the agency's internal interpretation of the law it is tasked to enforce.
Procedural Rules: These govern the internal operations and the conduct of proceedings before the agency.

Requisites for Validity:

For an administrative rule to be valid, it must:

Be issued under authority of law.
Not contravene the Constitution or the enabling statute.
Be reasonable.
Comply with publication requirements (usually in the Official Gazette or a newspaper of general circulation) and be filed with the Office of the National Administrative Register (ONAR).

III. Quasi-Judicial (Adjudicatory) Power

This is the authority to hear and determine questions of fact and law, similar to a court. Agencies exercise this power when they resolve disputes between parties or determine the rights of individuals under the law.

Administrative Due Process:

The landmark case of Ang Tibay vs. Court of Industrial Relations established the "Seven Cardinal Primary Rights" in administrative proceedings:

The right to a hearing.
The tribunal must consider the evidence presented.
The decision must have something to support itself.
The evidence must be substantial (such relevant evidence as a reasonable mind might accept as adequate to support a conclusion).
The decision must be rendered on the evidence presented at the hearing.
The body or any of its judges must act on its or his own independent consideration of the law and facts.
The decision should be rendered in such a manner that the parties can know the various issues involved and the reasons for the decisions rendered.

IV. Determinative Powers

To effectively carry out their functions, agencies are often granted "determinative" powers that fall between pure administration and adjudication:

Enabling Power: Granting licenses or permits (e.g., the LTFRB granting a franchise).
Directing Power: The power to issue orders or commands to do or refrain from doing an act (e.g., a Cease and Desist Order from the DENR).
Dispensing Power: The authority to exempt certain items or persons from the operation of a rule (e.g., granting a zoning variance).
Summary Power: The power to take immediate action without a prior hearing in urgent situations, such as the abatement of a per se nuisance or the seizure of mislabeled drugs.

V. Fact-Finding and Investigative Power

Agencies must be able to gather information to fulfill their roles. This includes:

The power to issue Subpoena Ad Testificandum (compelling attendance of witnesses).
The power to issue Subpoena Duces Tecum (compelling production of documents).
The power to conduct inspections and audits.

Note: Unlike courts, administrative agencies generally cannot punish for contempt directly unless the law specifically grants them that power. Usually, they must apply to a Regional Trial Court to enforce contempt charges.

VI. Doctrines Limiting Judicial Intervention

Courts generally respect the expertise of administrative agencies through two key doctrines:

Doctrine of Exhaustion of Administrative Remedies: A party must use all available remedies within the administrative agency before seeking help from the courts. Failure to do so makes the court case premature and dismissible.
Doctrine of Primary Jurisdiction: If a case involves a highly technical matter within the expertise of an agency, the court will not resolve the matter even if it has jurisdiction, but will instead refer it to the agency for a prior determination.

VII. Judicial Review of Administrative Action

While agencies have broad powers, they are not above the law. Their actions are subject to judicial review if:

The agency acted without or in excess of jurisdiction.
There was a Grave Abuse of Discretion amounting to lack or excess of jurisdiction.
The action was based on an error of law.
The findings of fact are not supported by substantial evidence.