- Data Transmission
- Deadweight Loss
- Debentures
- Debt
- Decatherm
- Decommissioning
- Decoupling
- Decoupling of Revenue and Output
- Decreasing Returns
- Decreasing Returns to Scale
- Decreasing-Cost Industry
- Deep Discounting
- Deflator
- Degree Day
- Demand
- Demand Curve
- Demand Curve, Movements Along
- Demand Side Management
- Demand, Annual Maximum
- Demand, Annual System Maximum
- Demand, Average
- Demand, Billing
- Demand, Charge
- Demand, Coincident
- Demand, Instantaneous Peak
- Demand, Law of
- Demand, Maximum
- Demand-Based Pricing
- Demerit Goods
- Demographics
- Dependability
- Depreciation
- Deregulation
- Derivatives
- Derived Demand
- Detaied Valuation Methodology (DVM)
- Developed Countries
- Developing Countries
- Deviation
- Dial Tone
- Differentiated Products
- Digital Subscriber Line (DSL)
- Digital Subscriber Loop Multiplex (DSLAM)
- Digital Transmission
- Diminishing Returns
- Direct Access
- Direct Connection
- Direct Costs
- Direct Load Control (DLC)
- Directory
- Directory Assistance
- Disaggregation
- Disbursement
- Disclosure Regulation
- Disclosures
- Disconnection
- Disconnection Notice
- Discount Plan
- Discount Rate
- Discounted Cash Flow
- Discriminating Monopoly
- Diseconomies of Scope
- Diseconomies of Scale
- Disequilibrium
- Dispatch, Dispatching
- Distributed Generation
- Distribution
- Distribution Channel
- Distribution Company
- Distribution Line
- Distribution of Income
- Distribution Service
- Distribution Utility (Disco)
- Disutility
- Diversifiable Risk
- Diversification
- Divestiture
- Division of Labor
- Dominant Carrier
- Dominant Firm
- Dominant Strategy
- Duopoly
- Durable Good
- Directory Assistance System (DAS)
