プログラム可能な中央銀行マネーの隠れたリスク

CBDCは貨幣をプログラム可能なインフラに変える可能性がある

Money has been becoming increasingly digital for decades. Salaries arrive through direct deposit, bills are paid online, and consumers routinely make purchases without touching physical cash.
Central bank digital currencies, or CBDCs, may appear to be the next step in this familiar transition. However, replacing cash with central bank-issued digital money would involve much more than changing how a payment reaches a merchant.

A CBDC could become a new layer of national financial infrastructure. Depending on how it is designed, it may determine who can access the payment system, what information is collected, which companies can build services around it, and whether conditions can be placed on how money is used.

That makes the development of CBDCs as much a question of governance and institutional power as one of payment speed.

中央銀行デジタル通貨とは何か？

A CBDC is a digital form of money issued by a country’s central bank. It would carry the same official status as physical cash, but exist electronically.

This separates CBDCs from cryptocurrencies such as Bitcoin (BTC ), which are not issued by a government. It also distinguishes them from stablecoins, which are usually issued by private companies and designed to maintain a stable value against a national currency.

CBDCs are different from the money already visible in a bank account as well. A bank deposit represents money held by a commercial bank. A CBDC would represent a direct form of central bank money, although commercial banks and payment companies could still help distribute it.

The distinctions matter because the issuer controls more than the currency’s name. It can also influence the rules, technical architecture, access requirements, and data practices surrounding it.

CBDCは単なる高速デジタル決済以上のもの

Central banks often present CBDCs as tools for improving payment efficiency, security, resilience, and financial inclusion. These benefits are possible, particularly in countries where banking services are expensive or difficult to access.

A well-designed CBDC could provide several practical advantages:

• 低コストの送金と高速決済
• 従来の銀行口座なしでの支払いアクセス
• ネットワーク障害時のオフライン取引
• 政府支払いのより効率的な配信

These capabilities could be particularly valuable in rural communities, developing economies, and areas where commercial banking infrastructure remains limited.

However, faster payments alone do not justify rebuilding part of a country’s monetary system. Many existing payment networks already move money quickly. The more significant development is that CBDCs could make sovereign money programmable, traceable, and directly integrated with digital services.

Those capabilities could change how money functions after it has been issued.

プログラム可能なマネーは新たな可能性を創出する

Programmability means rules can potentially be attached to digital money or to the systems through which it moves.

Governments could use this capability to automate tax collection, distribute emergency assistance, or ensure that certain benefits are spent on their intended purpose. A relief payment could be made available immediately after a natural disaster. A subsidy could automatically expire once a program ends. Cross-border transfers could settle when predefined conditions are met.

Smart contracts could also reduce administrative work by executing payments automatically. Businesses might receive funds when goods are delivered, while regulators could gain faster access to information needed to detect fraud or money laundering.

These are meaningful benefits. Yet the same tools could also restrict financial choice.

A government payment could be limited to approved products, regions, or periods. Transactions could become easier to monitor. Access could potentially be linked to digital identity systems, compliance status, or other conditions.

Not every CBDC will include these features. In fact, central banks may deliberately limit programmability at the currency level. The larger point is that CBDCs create the technical capacity to embed policy into payment infrastructure. Whether that capacity is used, restricted, or prohibited will depend on design and law.

プライバシーはローンチ前に確立されなければならない

Physical cash provides a degree of anonymity by default. A person can purchase an ordinary legal product without creating a permanent digital record held by a financial institution.

CBDCs may not preserve that characteristic.

Transaction records can help combat fraud, tax evasion, and criminal financing. However, a system that records every payment can also produce an unusually detailed picture of a person’s life. Purchases can reveal medical conditions, political interests, religious affiliations, travel patterns, and personal relationships.

Privacy therefore cannot be treated exclusively as a cybersecurity feature. Encryption may protect data from hackers without preventing authorized institutions from collecting, retaining, or analyzing it.

A credible CBDC would need clear limits governing what data is collected, who can access it, how long it is retained, and under what circumstances identities can be revealed. These protections may need to be supported by legislation and independent oversight rather than relying entirely on promises made during development.

Without credible safeguards, the people most concerned about surveillance may avoid the system. That could undermine adoption and weaken the financial inclusion argument used to support CBDCs in the first place.

研究は証拠が依然として限られていることを示す

A 2026 study¹ from researchers at the University of Queensland helps place these issues in context. The researchers reviewed 133 peer-reviewed CBDC studies published between 2018 and 2025年1月.

Rather than treating CBDCs solely as new monetary instruments, they examined them as systems shaped by technology, institutions, governance, and competing interests. The review identified four central areas of research: technical design, implementation and adoption, governance, and broader societal consequences.

Its most important finding may be how much remains unknown.

Approximately 37.6% of the reviewed research was conceptual, while another 16.5% relied on modelling or simulation rather than real‑world evidence. Claims that CBDCs will expand financial inclusion, improve monetary policy, or transform financial services therefore remain largely unverified.

This does not mean those benefits will not materialize. It means governments are considering infrastructure with potentially far‑reaching consequences before many of its promised advantages and risks have been tested at scale.

The researchers also found that privacy and surveillance are frequently framed as engineering problems. That approach can overlook a more fundamental question: who should have the authority to observe, restrict, or condition lawful financial activity?

CBDCは商業銀行を再構築する可能性がある

CBDCs may also change the role of commercial banks.

Today, banks use customer deposits to support lending and other financial activities. If consumers move significant amounts into central bank money, commercial banks could lose part of that deposit base. Funding may become more expensive, potentially affecting credit availability.

This risk could become more pronounced during periods of financial stress. Moving money from one commercial bank to another takes effort and may not feel completely safe. Moving it into a government‑backed digital wallet could be easier, potentially accelerating a digital bank run.

Central banks can reduce this risk through holding limits, tiered interest rates, or distribution models that keep commercial banks involved. These decisions would influence whether CBDCs compete with existing institutions or operate through them.

The same choices will shape the opportunity available to payment processors, wallet providers, cybersecurity firms, identity platforms, and financial software companies. A closed CBDC could concentrate control within the central bank. A more open system could support an ecosystem of regulated private services.

VisaはCBDC統合へのエクスポージャーを提供する

For investors, Visa Inc. (V ) is one publicly traded company relevant to the development of CBDCs.

Visa does not issue sovereign currency, nor does its investment case depend on CBDCs being widely adopted. Its opportunity comes from helping different forms of money move between consumers, merchants, financial institutions, and digital platforms.

The company has explored CBDC payment infrastructure, interoperability, offline transactions, and ways to connect digital currencies with existing wallets and merchant networks. That expertise could make Visa an important integration layer if central banks choose systems that rely on private payment providers.

Visa also brings an established global network, relationships with financial institutions, fraud‑management capabilities, and experience navigating different regulatory environments. These assets would be difficult for a newly created CBDC system to reproduce quickly.

The investment case is not without risk. A CBDC designed to move directly between central banks, consumers, and merchants could bypass parts of the existing card‑payment model. Governments may also favour domestic infrastructure or limit the role of foreign payment companies.

Visa should therefore be viewed as a potential bridge between old and new payment systems, not an automatic winner. Its relevance comes from its ability to connect competing forms of money while remaining useful regardless of which one gains the most adoption.

ルールは技術よりも重要になる

CBDCs could make payments faster, expand access, and create more responsive financial services. They could also normalize a level of monetary visibility and control that does not exist with physical cash.

The outcome will not be determined by whether a CBDC uses blockchain or another database. It will depend on decisions about privacy, programmability, access, interoperability, and the division of responsibility between central banks and private companies.

Those choices are being made now, while much of the supporting research remains conceptual. Investors and consumers should therefore look beyond announcements about digital currency launches. The more important question is what kind of financial infrastructure is being built, who is allowed to participate, and which protections are difficult to remove once the system becomes essential.

References:

^{1. Huang, W., & Breidbach, C. F. (2026). Central bank digital currencies: What is known and yet to be known? Journal of Strategic Information Systems, 35, 101978. https://doi.org/10.1016/j.jsis.2026.101978}