Part I of this article reviews major differences in definitions of the transaction concept by leading authors and some of the difficulties involved in its usage. Part II takes steps towards a new approach, starting with the legal notion of a contract. This identifies a narrower and more specific type of transaction, empowered by both legal forces and non-legal or cultural norms or rules. The sharper and more specific concept of contracting cost is derived. Contracting costs are the costs of obtaining, formulating, negotiating, and administering legal contracts. They do not include the costs of the work and other inputs required to fulfil a specific contractual agreement. Legal contracts are historically specific phenomena, applying only to modern societies with developed legal institutions. By making the analysis more specific, we emphasise factors of greater relevance in modern market economies. In addition to legal sanctions, the law engenders other forms of motivation based on what is perceived to be legitimate legal authority.

The paper analyses the potential impact on monetary policy transmission stemming from the adoption of a central bank digital currency (CBDC). Bank funding conditions and potential profitability effects are the main channels through which CBDC could have a bearing on monetary policy transmission via banks. As is the case for banknotes, the central bank balance sheet identity operates in effect as an aggregate consistency restriction that prevents CBDC from creating funding scarcity for the banking system as a whole. However, without policy neutralising actions, the new resulting bank funding mix might be less favourable for banks, thus potentially leading to suboptimal outcomes from a monetary policy perspective, such as restrictions in credit supply. Analysing the transmission channels through which banks obtain the necessary reserves suggests that a CBDC could have a material impact on bank lending conditions only if some relevant frictions, such as collateral constraints or liquidity shortages, materialise. Adverse funding conditions, such as those arising from lower bank liquidity or difficulty to access central bank funding or to tap the bond market, further paired with a large demand for CBDC, could affect bank lending conditions and the transmission of monetary policy. Importantly, even in this case, careful design, and implementation, as well as attentive communication can limit an unwarranted tightening coming from funding and liquidity tensions due to the rollout of CBDC. In addition, the central bank could take specific action to prevent or neutralise unwarranted impacts in order to maintain its desired monetary policy stance. In the longer term, a digital euro could support the digitalisation of the euro area banking sector, levelling the playing field for banks more exposed to competition from new players like big tech firms.

Risk was incorporated into monetary aggregation over thirty-five years ago, using a stochastic version of the workhorse money-in-the-utility-function model. Nevertheless, the mathematical foundations of this stochastic model remain shaky. To firm the foundations, this paper employs richer probability concepts than Borel-measurability, enabling me to prove the existence of a well-behaved solution and to derive stochastic Euler equations. This measurability approach is less common in economics, possibly because the derivation of stochastic Euler equations is new. Importantly, the problem’s economics are not restricted by the approach. The results provide firm footing for the growing monetary aggregation under risk literature, which integrates monetary and finance theory. As crypto-currencies and stable coins garner attention, solidifying the foundations of risky money becomes more critical. The method also supports deriving stochastic Euler equations for any dynamic economics problem that features contemporaneous uncertainty about prices, including asset pricing models like capital asset pricing models and stochastic consumer choice models.

Debates on dedollarizing and internationalizing China’s currency, the renminbi (RMB), often focus on state-led initiatives such as bilateral currency swaps and Central Bank Digital Currencies while overlooking the role of entrepreneurs utilizing US dollar (USD) alternatives. Ethnographic fieldwork with Nigerian importers of Chinese goods reveals how parallel payment currencies and channels—informal naira-RMB transfers and illicit cryptocurrency transactions—are just as essential in the Global South to decenter US dominance: its currency, institutions, and authority. Analyzing formal monetary policies and local money practices, Liu shows how Nigerian importers cultivate multicurrency fluency, which is vital in an incipient era of political and economic multipolarity.

Inspired by Clower’s conjecture that the necessity of trading through money in monetised economies might hinder convergence to competitive equilibrium, and hence, for example, cause unemployment, we experimentally investigate behaviour in markets where trading has to be done through money. In order to evaluate the properties of these markets, we compare their behaviour to behaviour in markets without money, where money cannot intervene. As the trading mechanism might be a compounding factor, we investigate two kinds of market mechanism: the double auction, where bids, asks and trades take place in continuous time throughout a trading period; and the clearing house, where bids and asks are placed once in a trading period, and which are then cleared by an aggregating device. We thus have four treatments, the pairwise combinations of non-monetised/monetised trading with double auction/clearing house. We find that: convergence is faster under non-monetised trading, implying that the necessity of using money to facilitate trade hinders convergence; that monetised trading is noisier than non-monetised trading; and that the volume of trade and realised surpluses are higher with the double auction than the clearing house. As far as efficiency is concerned, monetised trading lowers both informational and allocational efficiency, and while the double auction outperforms the clearing house in terms of allocational efficiency, the clearing house is marginally better than the double auction in terms of informational efficiency when trade is through money. Crucially we confirm the conjecture that inspired these experiments: that the necessity to use money in trading hinders convergence to competitive equilibrium, lowers realised trades and surpluses, and hence may cause unemployment.

The concept of monetary sovereignty employed by Modern Monetary Theory has been criticised on many fronts. One of the most important criticisms points out that Modern Monetary Theorists (MMTers) ignore or underestimate problems arising from external constraints. Another important (and complementary) criticism is that MMTers focus only on purely macroeconomic aspects and ignore political and geopolitical issues. In this paper, we discuss these important criticisms and we conclude that, although the MMT concept of monetary sovereignty is useful and can be considered an analytical advance, it is incomplete and biased because it minimises macroeconomic problems arising from external constraints and because it does not take into account international political factors.

During the 1690s, both the English and Ottoman states developed new institutions for longer-term borrowing and reformed their imperial monetary systems. These synchronous but divergent developments present a puzzle that has not been answered by rigidly separate English and Ottoman historiographies. “Empires of Obligation” follows merchants trading between England and the Ottoman Empire to understand how both states responded differently to the challenges of global trade and fiscal crisis. At this time, English merchants were the most powerful European traders in the Ottoman Empire, and the Ottoman Empire represented England’s greatest single market for its woolen textiles, its largest industry. As Levant Company merchants swapped woolens for silk, they also blended international private credit with domestic public finance. They were the largest merchant investors relative to the size of their trade in the Bank of England and helped facilitate Ottoman longer-term public borrowing through the mālikāne system. From within England’s bureaucracy, they also worked to ease global trade through an “intrinsic value” theory of money, the idea that coins represented a government commitment to provide a fixed amount of precious metal. At the same time, the Ottoman state sought to redefine money as an instrument of the state, not a tool of trade. Following merchants who themselves bridged two empires that are rarely compared shows interconnected but divergent responses to the challenges of making money work both within and between states at the end of the seventeenth century.

In a monetary model based on Lagos and Wright (2005) where unsecured credit and money are used as means-of-payments, we analyze how the cost and quality of the record-keeping technology affect welfare. Specifically, monitoring agents’ debt repayment is costly but is essential to the use of unsecured credit because of limited commitment. To finance this cost, fees on credit transactions are imposed, and the maximum credit limit that is incentive compatible depends on such fees and monitoring level. Alternatively, the use of money avoids such costs. A higher credit limit does not necessarily improve welfare, especially when the limit is high: the benefit from increased trade surpluses from a higher credit limit is offset by the increased cost of monitoring to achieve the improvement. Moreover, under the optimal arrangement, optimal credit limit decreases with the marginal cost of monitoring. When the cost is sufficiently low, a pure credit equilibrium is optimal. When the marginal cost is high, it is optimal to have a pure-currency economy. But when the cost is at an intermediate level, we show that credit is sustainable but not socially optimal. In this range, the implementable credit limit leads to a higher trade surplus than in a pure monetary economy, but owing to the cost of operating the record-keeping system, social welfare in credit equilibrium is lower than the welfare in a pure monetary equilibrium. In addition, we show that there can be a non-monotonic relationship between the optimal record-keeping level and the optimal credit limit.