Where the words come from
The unregulated natural monopoly at MR = MC with economic profit; a regulated price where average cost meets demand, giving a lower price, a higher quantity and a normal profit; a price at marginal cost as the efficient allocation, below average cost and so loss-making without a subsidy — Principles of Economics 2e, OpenStax, licensed CC BY 4.0. https://openstax.org/books/principles-economics-2e/pages/11-3-regulating-natural-monopolies. Changes: Figure 11.3's points A, F and C redrawn as an abstract chart with our own curves and no figures; "economic profits" called supernormal profit; the split-into-two option left to the live module is-competition-policy-worth-it; British spelling.
Mergers can reduce competition and lead to higher prices, reduced availability, lower quality and less innovation; regulators can allow, prohibit or allow a merger on conditions such as selling off parts; the government approves most mergers and the FTC says most benefit consumers by letting firms operate more efficiently — Principles of Economics 2e, OpenStax, licensed CC BY 4.0. https://openstax.org/books/principles-economics-2e/pages/11-1-corporate-mergers. Changes: US regulators generalised to "a regulator", with the UK authority named from GOV.UK; the Johnson & Johnson example reduced to the condition of selling part of the business; "lower costs can feed through to lower prices" and the closing sentence of the mistake note are ours; the merger-control definition recast from the allow/prohibit/conditions sentence.
US airline deregulation from 1978: entry, fares down by about one-third over two decades, fuller flights, more cities served, bankruptcies and job losses, while passenger numbers and airline jobs doubled; the meaning of deregulation; regulatory capture; the list of policies (blocking anticompetitive mergers, ending restrictive practices, price caps, deregulation) that strengthen the incentives of competition — Principles of Economics 2e, OpenStax, licensed CC BY 4.0. https://openstax.org/books/principles-economics-2e/pages/11-4-the-great-deregulation-experiment. Changes: The Clear It Up on airline deregulation condensed to one sentence of effects, with "half to two-thirds full" put as "flew fuller"; capture reduced to one clause, since the live module monopoly-regulation teaches it; British spelling.
Ofwat's addition of performance commitments with rewards and penalties at the 2014 price review, to stop water companies cutting costs by cutting service or damaging the environment — Independent Water Commission, Final Report (21 July 2025), GOV.UK, Open Government Licence v3.0. https://assets.publishing.service.gov.uk/media/687dfcc4312ee8a5f0806be6/Independent_Water_Commission_-_Final_Report_-_21_July.pdf. Changes: Summarised in our own words as on the live module monopoly-regulation; the effects on cost, profit, price and choice are our analysis, not the report's.
The Competition and Markets Authority assesses how mergers could affect competition in the UK — Mergers: how to notify the CMA of a merger, GOV.UK, Open Government Licence v3.0. https://www.gov.uk/guidance/mergers-how-to-notify-the-cma-of-a-merger. Changes: One clause of the merger explain block, in close paraphrase.
Questions, options, diagrams and feedback are our own. Figures credited to a source above are that source's; every other figure is invented to show the method.