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DOC MT–GM1 Partner register Entry 06 Rev. 2026.08 Status — on the register

A class is an economic
argument before it is a list.

GMT Economics sits on the Mediatasks partner register as a competition economics specialist — led by Dr Claudio Calcagno, who applies microeconomics to competition cases and has advised on UK collective actions before the Competition Appeal Tribunal.

In collective proceedings the economics decides the class: the theory of harm, the market, and where the boundary falls. That definition is what a participation programme then has to reach, register and evidence. Drafted apart, the two disagree — and the register fills with people who are not in the class.

Mediatasks

Participation infrastructure

A claimant journey built to the class definition, and able to evidence it.

+
GMT Economics

Competition economics

The theory of harm, the market, and where the class boundary falls.

Fig. 00 — the pairing. Two disciplines, one case file. Neither substitutes for the other.

Tab 02 · The gap MT–GM1 / 002
Clause 02The gap it closes

Eligibility is an economic question first

A registration journey asks a claimant a series of questions to establish whether they qualify. Every one of those questions sits downstream of an economic argument: what the market is, what the harm was, and who was exposed to it.

We design and operate the journey. We do not form the economic opinion that sets its boundary — and a participation team improvising one is a liability at certification, not an efficiency.

Build the register to the class definition. Not to a guess at it.

Tab 03 · Failure modes MT–GM1 / 003
Clause 03Where it breaks

Four ways a register stops matching its class

Each of these is created at case design and discovered at certification, which is the worst possible order in which to find it.

GM–01

Intake designed before the class was

Registration questions written while the class definition was still moving.

GM–02

Criteria the data cannot evidence

A definition sound in economics and unprovable from what was actually collected.

GM–03

Commonality under challenge

The class is attacked as too broad or too varied, and the register cannot show otherwise.

GM–04

Methodology that arrives with the report

The data the model needs was never captured, because nobody asked for it at stage one.

Tab 04 · The firm MT–GM1 / 004
Clause 04Who GMT Economics are

Making sense of economic evidence

GMT Economics is a London competition economics practice founded in 2021 and led by Dr Claudio Calcagno, an economist who specialises in applying microeconomics to competition cases. He has worked as a professional economist since 2004, holding senior roles at leading economic consultancies before founding the firm.

He has advised on more than a hundred matters and appeared before the Competition and Markets Authority, UK sector regulators, the Competition Appeal Tribunal, the High Court of England and Wales and the European Commission, as well as competition authorities and courts across the EU and further afield. Lexology Index clients describe “impressive analytical economic skills allied to a high degree of commercial awareness”.

Firm
GMT Economics Ltd — competition economics, founded 2021
Base
London
Principal
Dr Claudio Calcagno, Founder & Director
Role
Competition economics: theory of harm, market and class definition, commonality, and economic methodology
Collective actions
UK collective proceedings arising from alleged abuse of dominance and anti-competitive agreements
Before
CMA · UK sector regulators · Competition Appeal Tribunal · High Court of England and Wales · European Commission
Also covers
Market studies and investigations, mergers, vertical and horizontal agreements, competition appeals, State aid
Standing
Published in peer-reviewed journals; co-author of a leading textbook on exclusionary practices; Lexology Index Client Choice Award 2025 for competition experts in England
Working style
Side by side with the case team, or a fresh pair of eyes on economics already prepared
Co-branding schedule Mark pending
Mediatasks × GMT Economics Set in Mediatasks type

The official GMT Economics mark drops into this frame on release of their brand pack. Until then the name is set in our own type rather than approximated.

Tab 05 · The join MT–GM1 / 005
Clause 05Where the two disciplines meet

Two columns. One case file.

The division of labour is deliberately clean. GMT Economics decides where the class boundary sits and why. We build the journey that finds people inside it and produces the evidence that they are.

Neither column reaches into the other. We do not opine on economics, and the economics is not adjusted to suit what is convenient to collect.

Column A · Mediatasks

Participation infrastructure

The claimant, end to end.

  • Class criteria translated into registration questions
  • Screening and validation against the definition as written
  • Evidence captured per claimant, to specification
  • One claimant record for the life of the case
  • Reporting on class composition and reach
+ The class definition
Column B · GMT Economics

Competition economics

The economic case, end to end.

  • Theory of harm and market definition
  • Class definition and commonality
  • Economic methodology for damages
  • Expert reports and evidence at certification
  • Testimony before the Tribunal or the court

Fig. 01 — the join. Column B draws the boundary; column A builds to it and evidences it. The class definition is the only shared surface.

Tab 06 · Interlock MT–GM1 / 006
Clause 06How the two interlock

Stage by stage

The economics leads and the infrastructure follows — but the infrastructure has to say early what it can and cannot prove, or the definition is written against data that will never exist.

FIG. 02 · NOTE

Stage 03 is the cheapest hour in the whole case.

One review of the registration journey against the class definition, before it goes live, prevents a register that cannot answer the question it was built to answer.

StageMediatasksGMT Economics
01
Case design
Participation feasibility: who is reachable, through what channel, at what cost. Theory of harm, the relevant market, and the economic shape of the class.
02
Class definition
A plain statement of what can be asked at intake and what can actually be evidenced. The class boundary and the commonality argument, in the words that will be filed.
03
Intake build
Criteria become questions, screening rules and validation logic in the live journey. Review that the journey tests the definition it claims to test, before it goes live.
04
Certification
Register evidence on composition, provenance and reach, produced in usable form. Expert report and economic evidence supporting the application.
05
Merits
Continuing evidence capture at claimant level as the case develops. Methodology developed against the actual data rather than an assumed data set.
06
Quantum
A validated book that matches the class as certified, claimant by claimant. Economic quantification, alongside the quantum partner where one is instructed.

A register that cannot evidence the class definition is a register the class definition cannot use.

Tab 07 · Output MT–GM1 / 007
Clause 07What the engagement produces

Documents, not introductions

A joint engagement that produces nothing but a warm handshake is not worth publishing. These are the artefacts the joint engagement is designed to put on your desk.

The economic opinion is the expert’s, owed to the Tribunal. Nothing about this arrangement touches that.

RefDeliverable
OUT–01 Economic framing noteThe theory of harm and the market, written early enough to shape the participation plan.
OUT–02 Class definition, implementableThe boundary expressed so that an intake journey can actually test it, question by question.
OUT–03 Data specificationWhat certification and the damages methodology will need from the register, agreed at stage one.
OUT–04 Intake conformity reviewA written check that the live journey tests the definition as filed, before the first claimant sees it.
OUT–05 Expert report and evidenceEconomic evidence for certification and for the merits, in the expert’s own name.
Standing & independence

An expert’s duty runs to the Tribunal or the court, not to the instructing firm and certainly not to us. Mediatasks takes the class definition as an input and reports honestly on what the register can and cannot evidence. We do not comment on the economics, and no part of this arrangement gives us reason to.

Tab 08 · Fit MT–GM1 / 008
Clause 08Where it fits

Earliest of all the entries

The partner register sits above the operating modes, not inside one. Whichever configuration of the Participation Operating System™ a matter runs on, the economics discipline attaches the same way.

It is the entry that pays back earliest, because it changes what the intake asks. Introduced after the journey is live, most of that value has already been spent.

Mode 01

CasePartners™

You hold the book. The question becomes whether the data you already have can evidence the class as defined.

Read the mode →
Mode 02

LeadPartners™

We build the book from nothing, so every registration question is written after the class definition rather than before it.

Read the mode →
Mode 03

ArbPartners™

US mass arbitration. Claims are individual, so eligibility is tested per claimant rather than certified once.

Read the mode →
Jurisdiction
UK (Competition Appeal Tribunal, High Court) · EU (European Commission and national competition authorities).
Case type
Collective proceedings founded on abuse of dominance or anti-competitive agreements; follow-on damages claims.
Best introduced
Before the class definition is settled, and certainly before the registration journey is built.
Also useful
As a fresh pair of eyes on economics already prepared, or where commonality is being challenged.
Not a fit
Matters where the harm is not economic in this sense — product liability, data breach and personal injury sit outside the discipline.
Tab 09 · Questions MT–GM1 / 009
Clause 09Questions of substance

Questions of substance

Isn’t this just the expert we would instruct anyway?+

Often it is the same role, and that is the point. The arrangement exists so the participation programme is built to the expert’s definition rather than in parallel with it. Instruction and independence are unchanged; what changes is that the intake and the economics are drafted in the same room.

How is this different from the quantum partner?+

Competition economics establishes the theory of harm, the market, the class and the methodology — the economic case itself. Quantum and analytics sizes the claim and reads the claimant book as a financial asset. They are complementary, they frequently run together, and the specification records which questions belong to which.

Does Mediatasks influence the economic opinion?+

No, and it would be a serious problem if we did. We take the definition as given and report plainly on what the register can evidence. Where something cannot be proven from the data, we say so — which is information, not influence.

We already have economists instructed.+

Then this is either a review role or nothing at all, and we will not push it. GMT Economics offers a fresh-pair-of-eyes review of economics already prepared, which is a narrower and cheaper engagement than leading it.

Our registration journey is already live. Is it too late?+

Not too late, but more expensive. A conformity review will establish what the current register can and cannot evidence, and what has to be asked of existing claimants retrospectively. That second exercise is the one worth avoiding.

How is the arrangement paid for?+

Each firm is paid for its own work, on terms agreed with you in writing before it begins. Neither firm pays the other for an introduction. The specification sets out the commercial basis in full.

Tab 10 · Next step MT–GM1 / 010
Clause 10Next step

Request the specification.

The joint specification sets out scope, how the class definition passes into the intake journey, the data specification, expert independence, and the commercial basis in full. Sent as a PDF, no call required.

Request the specification

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