# The regulated monopoly: why utilities earn a guaranteed return
A utility executive sits at a witness table, sworn in like a courtroom defendant. Across from her, a panel of state commissioners. At stake: whether her company can raise electricity rates for three million customers. She is not arguing about market demand or competition. She is arguing that her company spent money prudently, and that the law entitles her to earn a profit on it.
Welcome to a rate case, the strange and consequential ritual at the heart of how most electric and gas utilities make money.
Building the poles, wires, pipes, and substations that deliver energy to your home costs an enormous amount of capital. It makes no economic sense to build three competing sets of power lines down the same street.
So society made a bargain. We grant one company an exclusive franchise (a legal monopoly) to serve a territory. In exchange, that company gives up the right to charge whatever it wants. A government regulator, usually a state Public Utility Commission (PUC), a body of appointed or elected officials, sets the prices instead.
This is the regulated monopoly. The company avoids competition. The public gets oversight.
Here is the core formula that governs utility profits. It is called cost-of-service regulation, and it works like this:
Revenue Requirement = Operating Expenses + Depreciation + Taxes + (Rate Base × Allowed Rate of Return)
Rate base is the total value of the capital assets a utility has built and put into service to serve customers: power plants, transmission lines, transformers, meters. Think of it as the utility's invested capital that regulators have approved.
Allowed rate of return is the percentage the utility is permitted to earn on that rate base. A key piece of this is the allowed ROE (return on equity), the profit rate on the shareholder-funded portion of the rate base. In recent US rate cases, allowed ROEs have commonly landed roughly in the 9 to 10 percent range, though this varies by state and year.
Multiply rate base by the allowed return, add operating costs, and you get the total money the utility is allowed to collect. Divide that across all customers, and you get your rates.
Back to our hearing. A rate case is the formal proceeding where a utility asks regulators to approve new rates. It can take a year or more.
The utility files testimony arguing for a bigger rate base and a healthy allowed ROE. On the other side sit intervenors: consumer advocates, large industrial customers, environmental groups, and the commission's own staff. They pick apart the filing.
The fights get specific:
The commission weighs the evidence and issues an order. That order sets rates until the next case.
If you want to see how granular this gets, the National Association of Regulatory Utility Commissioners publishes accessible primers on ratemaking.
Now the twist that makes this topic so important.
Look at the formula again. Utility profit comes from Rate Base × Allowed Return. A utility earns money on capital it invests, not on gas or electricity it sells.
So the surest way for a utility to grow its profits is to grow its rate base. Build more. A new substation, a new transmission line, a grid modernization program: each one adds to rate base, and each one earns the allowed return for decades.
This is often called the Averch-Johnson effect (economists Harvey Averch and Leland Johnson described it in 1962): regulated utilities have an incentive to over-invest in capital because capital is what they earn a return on.
The incentive is not evil. It has funded a century of reliable infrastructure. But it creates a bias toward the expensive, capital-heavy solution.
Suppose a utility could either:
1. Build a new $500 million power plant, or
2. Pay customers to install efficient appliances and reduce peak demand, avoiding the plant entirely.
Option 2 is cheaper for society. But under classic cost-of-service, option 1 grows rate base and profits, while option 2 does not. The utility is financially rewarded for the wasteful choice.
This is why energy efficiency has historically been a hard sell inside utilities. Helping customers use less of your product cuts into the very asset base your profits depend on.
The same tension shows up in the clean energy transition.
Some decarbonization is capital-heavy: large solar farms, battery storage, new transmission to reachreachThe number of unique people exposed to your message in a given period. Unlike impressions, reach counts each person once, no matter how often they see it.Voir la définition complète → wind resources. Utilities often like these, because they grow rate base.
But other decarbonization tools are not utility capital at all: rooftop solar owned by customers, distributed batteries, demand response (paying customers to cut usage when the grid is stressed), or simply using existing wires more cleverly with software. These can shrink the need for utility-owned iron, and therefore threaten the rate base.
So a utility might, entirely rationally under the old rules, favor a new gas plant over a portfolio of customer-owned resources, even when the second is cheaper and cleaner.
Vérification des acquis
1. Why does society typically grant utilities a legal monopoly over a service territory rather than allowing competition?
2. In the cost-of-service model, on which component does a utility actually earn its profit?
3. A utility executive at a rate case argues primarily that her company 'spent money prudently.' Why is prudence central to whether costs enter the rate base?
4. Select ALL correct answers about the regulatory bargain between utilities and the public.
Sélectionnez toutes les réponses correctes.
5. Select ALL correct answers about the components of the Revenue Requirement formula.
Sélectionnez toutes les réponses correctes.
Regulators have noticed the problem, and reform is a major theme heading into 2026.
Decoupling breaks the link between a utility's revenue and the volume of energy it sells. With decoupling, if customers use less because of efficiency programs, the utility still collects its approved revenue through small rate adjustments. This removes the penalty for helping customers save energy. Many US states have adopted some form of it.
Performance-based regulation (PBR) goes further. Instead of paying utilities mainly for spending capital, PBR ties a portion of their earnings to outcomes: reliability, customer satisfactioncustomer satisfactionCustomer Satisfaction Score, a direct measure of satisfaction captured right after a specific interaction or experience, usually on a short rating scale.Voir la définition complète →, emissions reductions, connecting clean energy quickly, or hitting affordability targets.
The United Kingdom pioneered a version of this called RIIO (Revenue = Incentives + Innovation + Outputs), run by its regulator Ofgem. It rewards network companies for delivering results, not just building assets. You can read Ofgem's overview of the RIIO framework.
In the US, states including Hawaii and New York have pushed performance-based models, partly to align utility profits with clean energy goals rather than against them.
If you work anywhere near energy, this model shapes almost everything.
A clean tech startup selling grid software has to understand that a utility may resist a solution that shrinks its rate base, unless regulation rewards efficiency. An investor evaluating a utility stock is really evaluating rate base growth and allowed ROE trends. A policymaker trying to accelerate decarbonization has to fix the incentive, not just set a target.
The regulated monopoly is not a relic. It is the operating system of the power sector, and understanding its incentives tells you why utilities behave the way they do.