Competition Law and User Pathway Design and Market Power

1. Introduction

User pathway design refers to the way a digital platform structures the sequence through which a user searches, compares, selects, purchases, subscribes, changes settings, communicates with sellers, or exits a service.

It includes:

• default settings;
• ranking and recommendation screens;
• search-result presentation;
• buttons and menus;
• pre-installed applications;
• choice screens;
• checkout flows;
• cancellation procedures;
• consent interfaces;
• payment pathways;
• prompts and pop-ups;
• interoperability and switching options; and
• the number of steps required to reach competing services.

The competition-law concern arises when a powerful platform uses control over the user pathway to influence demand in favour of itself or affiliated businesses, raise rivals' costs, increase switching costs, restrict access to competitors, or prevent users from discovering alternatives.

The UK's Competition and Markets Authority has expressly examined online choice architecture (OCA) as a competition issue, noting that interface design can influence consumer choices and potentially weaken competitive pressure.

2. Meaning of User Pathway Design

A user's digital journey can be represented as:

Entry → Search → Ranking → Comparison → Selection → Transaction → Post-sale use → Switching/Exit

A platform may control every stage.

For example:

User opens smartphone → searches for an app → sees platform's own service first → clicks it → payment occurs through platform → alternative provider is difficult to reach → switching requires additional steps.

Each individual design choice may appear commercially ordinary. The competition-law question is whether the combined pathway has the effect or capability of excluding rivals or exploiting users where the platform possesses substantial market power.

3. Relationship Between User Pathway Design and Market Power

User pathway design becomes particularly important in digital markets because platforms can possess:

A. Network effects

More users attract more sellers and developers, while more sellers attract more users.

B. Data advantages

The platform observes searches, clicks, purchases, browsing behaviour and conversion rates.

C. Default advantages

Users frequently retain the default option rather than actively searching for alternatives.

D. Switching costs

Moving to another platform may require transferring data, learning a new interface or abandoning accumulated purchases, contacts or reputation.

E. Attention advantages

The platform controls what users see first.

F. Ecosystem effects

A company may control several connected products—operating system, browser, search engine, app store, payments and advertising.

Consequently, control over the pathway can itself become an important competitive asset.

4. Competition-Law Theories of Harm

4.1 Self-preferencing

A dominant platform may place its own products or services more prominently than competing products.

Example:

Search → platform-owned service appears prominently → competing service is pushed downward.

This can reduce rivals' ability to obtain users even where they offer competitive prices or quality.

The Google Shopping litigation is particularly important here. The Court of Justice considered Google's favouring of its own specialised shopping results and the resulting effects on competing comparison-shopping services.

4.2 Default manipulation

A platform can make its own service the default while technically permitting users to change it.

The distinction is important:

Formal ability to switch ≠ economically effective ability to switch.

If changing the default requires numerous screens while accepting the platform's default requires one click, the pathway may substantially influence user behaviour.

4.3 Steering

Steering occurs where a platform influences users toward a particular commercial option.

Examples include:

• directing users toward the platform's payment system;
• directing users toward affiliated sellers;
• discouraging external purchases;
• restricting external links;
• presenting competing offers less prominently.

The European Commission's Digital Markets Act enforcement has specifically addressed steering and choice architecture involving major gatekeepers.

4.4 Tying and bundling

A user pathway may combine several products so that choosing one effectively results in adoption of another.

For example:

Operating system → compulsory/default search → browser → associated services.

The classic Microsoft cases demonstrate how integration and defaults can reinforce market power.

5. Six Important Case Laws

Case 1: Google Search (Shopping) — Google LLC and Alphabet Inc. v European Commission

This is one of the most significant cases concerning ranking and pathway design.

Google operated a dominant general search engine while also operating its specialised comparison-shopping service.

The Commission found that Google systematically gave prominent placement to its own comparison-shopping results while competing services were subject to generic search algorithms.

The issue was therefore not merely the existence of Google's shopping service. It concerned how users were guided through the search-results pathway.

The Court of Justice's 2024 judgment upheld the essential finding of abusive conduct under Article 102 TFEU.

Competition-law principle

A dominant platform cannot necessarily use control over a gateway to systematically favour its own downstream service where the conduct departs from competition on the merits and is capable of restricting competition.

Relevance to user pathway design

Search architecture → visibility → clicks → traffic → commercial success.

Thus, ranking design can function as a competitive instrument.

Case 2: Google Android — European Commission Android Decision

The Google Android proceedings concerned Google's contractual arrangements surrounding Android, including tying and restrictions affecting competing services.

The Commission examined the relationship between Android, Google Play, Google Search and Chrome.

The concern was that Google's arrangements could reinforce the position of Google Search by giving it privileged access to Android users.

The Commission rejected Google's justification for certain forms of tying involving Search and Chrome and the Play Store.

Competition-law principle

A dominant undertaking may not use control over an important platform or operating system to extend or protect its position in adjacent markets through restrictive arrangements.

User-pathway relevance

The pathway could operate as:

Android device → Play Store → Google Search/Chrome → continued Google ecosystem use.

The case demonstrates why defaults, pre-installation and ecosystem integration can be competition-law relevant.

Case 3: Microsoft v Commission — Windows Media Player

The Microsoft Windows Media Player case is a foundational authority on tying.

Microsoft's dominant Windows operating system was bundled with Windows Media Player.

The European Commission concluded that Windows and Windows Media Player were separate products and that the bundling could foreclose competing media players.

The General Court upheld the Commission's central findings, including the importance of Windows Media Player's ubiquitous presence on Windows PCs.

The Court emphasised that Microsoft's bundling created an advantage unrelated to competition on the merits because competitors could not obtain comparable distribution merely through their own product quality.

User-pathway relevance

The relevant pathway was:

Purchase Windows → Media Player already present → user encounters Microsoft product first → competing player must overcome Microsoft's installed position.

The case is particularly important because it demonstrates that distribution and interface position can alter competitive conditions.

Case 4: Amazon Marketplace — Buy Box and Marketplace Conduct

The European Commission's Amazon Marketplace investigation examined Amazon's treatment of third-party sellers, including the Buy Box.

The Buy Box is a highly prominent purchasing interface through which consumers can select an offer.

The Commission's investigation examined whether Amazon's practices could favour particular offers and whether Amazon's use of non-public marketplace data could benefit its own retail business.

Amazon ultimately offered commitments concerning seller data, Buy Box selection and logistics.

Competition-law significance

The case illustrates the importance of:

• prominence;
• default purchasing interfaces;
• ranking;
• platform neutrality;
• access to consumer attention; and
• conflicts between platform and marketplace functions.

User-pathway model

Product page → Buy Box → consumer's purchase decision.

If the Buy Box controls a substantial portion of transactions, its design can become an important competitive bottleneck.

Case 5: Apple App Store — Epic Games v Apple

The dispute between Epic Games and Apple concerned Apple's App Store rules, including restrictions concerning alternative payment mechanisms and external steering.

A central issue was whether Apple's control over the App Store pathway could restrict developers' ability to direct consumers toward alternative purchasing arrangements.

The litigation illustrates an important competition-law concept:

Control over the interface can determine whether rivals can reach consumers.

The litigation remains active in the United States, with further proceedings concerning Apple's compliance with earlier judicial orders reported in 2026.

User-pathway significance

Consider:

App discovery → App Store listing → purchase → Apple payment interface.

If alternative payment or purchasing routes are difficult to communicate, the platform potentially controls both consumer attention and transaction access.

Case 6: CCI — Google Android Ecosystem / Android TV Proceedings in India

Indian competition law also provides important examples.

The Competition Commission of India has examined Google's conduct concerning Android and associated ecosystem restrictions.

In the Android TV matter, allegations included compulsory bundling of Play Store with Android TV OS and restrictions concerning rival Android forks. In April 2025, the CCI approved Google's settlement proposal in the matter.

The broader Android proceedings are important because the CCI considered how Google's control over the Android ecosystem could affect competing search and mobile services.

User-pathway relevance

A device ecosystem can establish the pathway:

Device → operating system → app store → search/browser → default services.

The Indian experience therefore demonstrates that pathway design is relevant not merely as a consumer-protection question but also as an ecosystem competition issue.

6. Choice Screens as a Competition Remedy

A particularly important remedy is the choice screen.

Instead of:

Device → Google Search automatically

the pathway becomes:

Device → Choice Screen → Search Provider A/B/C/D → User selects default.

Following the CCI's Android decision, Google introduced a choice screen for eligible general search providers on new Android devices shipped in India. The screen allows users to select a search provider during device setup.

This demonstrates an important regulatory principle:

Competition law can sometimes modify the architecture of choice itself rather than merely imposing a financial penalty.

7. Dark Patterns and Competition

User pathway design overlaps with the concept of dark patterns.

Examples include:

Confirmshaming

The alternative to accepting an option is presented negatively.

Forced continuity

A free trial automatically becomes a paid subscription.

Roach motel

Entering a service is easy but leaving is difficult.

Sneak into basket

Additional products are introduced into the purchasing pathway.

Hidden alternatives

A competing or less profitable option requires additional navigation.

Pre-selected defaults

The platform chooses an option unless the consumer actively changes it.

The CMA has identified 21 forms of online choice architecture and categorised them broadly around choice structure, choice information and choice pressure.

8. When Does Interface Design Become a Competition Problem?

Not every persuasive interface is unlawful.

A competition-law analysis should ask:

Step 1 — What is the relevant market?

Examples:

• general search;
• mobile operating systems;
• app distribution;
• online marketplaces;
• digital advertising;
• food-delivery platforms.

Step 2 — Does the undertaking possess market power?

Relevant indicators may include:

• market share;
• entry barriers;
• network effects;
• switching costs;
• control of data;
• ecosystem dependence;
• technological advantages.

Step 3 — What exactly is the pathway?

Map the user's journey:

Entry → discovery → ranking → selection → payment → post-purchase → exit.

Step 4 — What competitive mechanism is affected?

Is the conduct affecting:

• price competition?
• quality?
• innovation?
• visibility?
• access?
• switching?
• interoperability?
• distribution?

Step 5 — Is there foreclosure?

Could competitors lose sufficient users, transactions, data or visibility to compete effectively?

Step 6 — Is there consumer exploitation?

Does the design cause:

• excessive prices;
• reduced quality;
• reduced privacy;
• reduced choice;
• increased switching costs?

Step 7 — Are there legitimate efficiencies?

The platform may argue that a particular design:

• reduces search costs;
• improves security;
• simplifies navigation;
• prevents fraud;
• improves interoperability;
• reduces transaction costs.

Those justifications must be considered against the competitive effects.

9. User Pathway Design as a Form of Market Power

A useful conceptual distinction is:

Traditional market power

"I control a large share of the market."

Digital pathway power

"I control how users reach the market."

The second can sometimes be more significant than market share alone.

For example:

Platform controls search → platform controls visibility → visibility controls traffic → traffic determines sellers' economic viability.

This creates a possible gateway effect.

10. Network Effects and Pathway Reinforcement

User pathway manipulation can create a feedback loop:

Dominant platform

↓

Preferential interface

↓

More user attention

↓

More transactions

↓

More seller participation

↓

More data

↓

Better algorithms

↓

Greater user engagement

↓

Stronger market position

This is why seemingly small interface changes can potentially have substantial long-term competitive consequences in markets characterised by network effects.

The CMA has specifically observed that harmful online choice architecture can weaken competition and allow firms with market power to maintain, leverage or exploit their position.

11. User Mobility and Exit Barriers

User pathway design is also closely connected with switching costs.

Suppose:

Joining competitor = 1 click

but

Leaving incumbent = 8 screens + cancellation call + data-export process + confirmation emails.

The nominal availability of the competitor does not necessarily mean that competition is fully effective.

Competition authorities may therefore examine:

• account portability;
• data portability;
• interoperability;
• default settings;
• cancellation processes;
• subscription renewal;
• external links;
• API access;
• switching costs.

12. Remedies

Possible competition-law remedies include:

1. Choice screens

Give users meaningful alternatives.

2. Anti-self-preferencing obligations

Require neutral ranking criteria.

3. Interoperability

Allow competitors to interact with the dominant platform.

4. Data portability

Allow users to move relevant data.

5. Anti-steering remedies

Permit businesses to inform users about alternative offers.

6. Default-setting reforms

Require easy switching of defaults.

7. Transparency

Require platforms to disclose relevant ranking or recommendation principles where legally appropriate.

8. Structural remedies

In exceptional circumstances, separation of platform and downstream commercial functions may be considered.

9. Monetary penalties

Fines can address completed infringements but may not by themselves correct a continuing pathway problem.

13. Competition Law vs Consumer Protection

The two areas overlap but are not identical.

Therefore, an interface can be problematic even when the principal legal theory is not traditional abuse of dominance.

14. Emerging Regulatory Approach

The modern approach increasingly recognises that competition can be affected by the architecture through which competition occurs.

The European Union's Digital Markets Act expressly addresses several forms of gatekeeper conduct involving steering, choice and self-preferencing. In 2024, the Commission investigated Alphabet, Apple and Meta over various DMA obligations, including steering and Apple's browser-choice screen.

In 2025, the Commission found Apple in breach of the DMA's anti-steering obligation and Meta in breach of an obligation concerning consumer choice involving personal-data use.

In July 2026, the Commission also announced €890 million in fines against Google in two DMA decisions involving self-preferencing on Search and restrictions on steering users toward alternative purchasing channels on Google Play.

The UK's CMA is similarly examining Google's presentation of search choices and choice architecture under its digital-markets regime.

15. Key Legal Principles

The principal principles emerging from these cases are:

1. Interface design can have competitive effects.
2. Defaults can confer substantial competitive advantages.
3. Visibility and ranking can constitute important competitive bottlenecks.
4. A dominant platform's control over user pathways can facilitate leveraging into adjacent markets.
5. Self-preferencing can distort competition where the platform controls access to users.
6. Tying and bundling can reinforce network effects and entry barriers.
7. Formal availability of alternatives does not necessarily establish effective competition.
8. Switching friction can protect market power.
9. Choice architecture can affect both consumer welfare and rival access.
10. Digital competition remedies increasingly address the architecture of choice itself.

16. Conclusion

User pathway design is becoming an important dimension of digital competition law because platforms do not merely participate in markets—they can control the route through which users reach those markets.

The central legal question is therefore not simply:

"Does the platform have market power?"

but also:

"How does the platform's control over the user's pathway affect the ability of rivals to compete?"

The Google Shopping, Google Android, Microsoft, Amazon Marketplace, Apple–Epic and Indian Android proceedings illustrate different versions of this problem: ranking, defaults, tying, bundling, Buy Box design, steering, app-store control and ecosystem restrictions.

Accordingly, a comprehensive competition-law assessment of user pathway design should examine market power + interface architecture + user behaviour + rival access + switching costs + foreclosure + efficiencies + remedy design.