Not the Whole Story: How Zero-Sum Thinking Distorts Payment Innovation
Zero-sum headlines declare “cash is dead” or frame BNPL as a credit-card killer. Fresh UK Finance data tell a different story: contactless, cash and BNPL are all growing; layered, not cannibalised. Here’s why clinging to win-lose narratives skews product bets and policy debates.

Zero-sum thinking is seductive. It offers the neatness of winners and losers; a comforting simplicity in a world that is anything but. When someone else gains attention, wealth, or market share, we instinctively fear that we've lost something in return. This mindset, born of scarcity and honed in tribal environments, once served a useful purpose. But in today's interconnected economy, it distorts more than it reveals.
Nowhere is this more evident than in public debates, where cause and effect are often not just misattributed but inverted. Contactless card usage rises, and we prematurely declare cash dead—overlooking demographic shifts, evolving security perceptions, and the pandemic’s catalytic role in reshaping payment norms. Buy Now, Pay Later (BNPL) surges, and we assume it is displacing credit cards; yet for many consumers, BNPL acts as an entry point into digital credit rather than a replacement. According to the UK Payment Markets 2024 report, contactless payments accounted for 38% of all UK transactions in 2023, with 85% of adults using them regularly, while cash usage fell to just 12%, continuing its long-term decline. BNPL usage also grew: 14% of adults used it in 2023, up from 12% the year before, with adoption especially concentrated among 25–34-year-olds, nearly one in four (24%) of whom used a BNPL service. These trends suggest not replacement, but expansion—new options layered atop old ones, not necessarily crowding them out.
This conflation of correlation with conflict, of sequence with causation, produces intellectual tunnel vision. It frames our choices as adversarial when they are often additive or orthogonal. Worse still, it blinds us to system-level dynamics unfolding beyond the immediate frame. Every reaction becomes a verdict; every trend, a referendum. In such an environment, second-order thinking doesn’t just become rare; it becomes radical.
Zero-sum thinking isn't merely a cognitive trap; it is an architectural bias embedded in our digital platforms. Systems are designed around conversion funnels and abandonment rates; revenue attribution is rooted in short-term outcomes. When decision-makers are accountable for metrics that reward visible gains, complexity and long-term impacts often fade from view. This leads them to decisions that 'move the needle' now but generate hidden costs or deferred risks later.
This tendency isn't just cognitive; it's experiential. Harvard economist Stefanie Stantcheva’s research [Stantcheva 2024] shows that people raised during periods of slower economic growth are more prone to seeing the world in zero-sum terms. In payments, this manifests as an assumption that every new method must displace an existing one rather than expanding the overall ecosystem. Interestingly, Stantcheva also found that urban areas exhibit more zero-sum thinking despite being exemplars of positive-sum coordination. Similarly, digital platforms, designed for mutual benefit through network effects, frequently foster zero-sum competition among payment methods, features, and user segments.
This is where Annie Duke's distinction between decision quality and outcome quality becomes crucial. A fraud model blocking fewer transactions isn't necessarily underperforming; it might simply be adapting to a changed threat landscape. Without documenting our reasoning beforehand, we retrofit explanations to fit outcomes. Metrics and feedback loops in payments often exemplify this trap. An A/B test might show higher conversions for one checkout flow, yet overlook downstream effects on customer satisfaction, support costs, or long-term retention. The metric rewards visible wins whilst obscuring distributed costs.
Apple Pay offers a practical illustration of positive-sum outcomes; its success didn’t diminish card usage but accelerated overall digital payment adoption. Similarly, Worldpay’s Global Payments Report reveals BNPL’s growth alongside traditional credit, especially among younger demographics previously reliant exclusively on debit.
For payment professionals, reframing how we evaluate new technologies and business models is essential. Instead of asking, 'Will mobile wallets kill cards?' we should ask, 'How might different payment methods serve distinct use cases and customer segments?' The question shifts from territorial competition to ecosystem thinking.
The choice isn’t between winners and losers; it's between clarity and confusion. As explored in 'Decision Journals: The Missing Link Between Frameworks and Results', the frameworks we use shape the outcomes we see. By replacing zero-sum frames with systems thinking, we move from reactive decision-making to proactive understanding. The first step is admitting that what we see isn't always what's there.