ABSTRACT Cocoa is Papua New Guineaʼs (PNG) third‐largest agricultural export, supporting about two million smallholder farmers. Despite integrated pest and disease management (IPDM) systems to improve yields, adoption remains low. We surveyed two cocoa‐growing households—one near Balima (Madang Province) and the other near Manetai (Bougainville)—and combined these data with expert knowledge and published data to model revenue, labour, and capital inputs for dry bean cocoa production under different IPDM input levels, assessing financial viability. Results show profitability depends on unpaid labour; monetising labour costs eliminates or reduces returns. When labour is not paid in cash—as is common in Indigenous exchange economies in PNG—the increased cost and effort required for dry bean production is justified by potential returns. Excluding labour costs significantly improves benefit cost ratios, peaking at medium IPDM input levels. While higher IPDM inputs increase long‐term returns, they reduce short‐term profitability. Finally, potential hourly net incomes remain below PNGʼs minimum wage, raising sustainability concerns. Policy priorities include raising farmgate prices and access to fermentaries and dryers.

Extremes of the Edgeworth box concern corner allocations and their relationship to the contract curve in a two-good, two-agent exchange economy. In the standard pure-exchange setting with well-behaved preferences, the contract curve comprises all Pareto-efficient allocations, including interior tangencies and boundary corners, where no mutually beneficial trade remains. When money is introduced as a numéraire (a medium of exchange only), real feasibility and preferences are unchanged, so the contract curve remains the benchmark for efficiency. When money provides liquidity services (is valued for holding), agents may rationally abstain from trade even near interior tangencies; short-run outcomes can therefore include inaction at corners. This entry defines these objects, outlines the efficiency conditions at boundaries, and summarizes how monetary interpretations affect short-run behavior in general equilibrium and monetary economics. The Edgeworth geometry remains a real-exchange depiction; when we discuss money as a store of value, we use it as a short-run, reduced-form outside option that proxies intertemporal motives. This does not “fix” the box; it clarifies why no-trade at or near corners can be individually rational when liquidity is valued.

We introduce the notion of committee-structured games (CSG) in a cooperative framework to analyze situations where committees affect players in generating their coalitional values. We represent the sets of committees by hypergraphs and obtain values as a function of both coalitions and hypergraphs. Based on how committee structures affect value generation, we present two models within the CSG framework. In the first model, the total value is generated by the committee set as a whole, while in the second model, it is obtained by aggregating contributions from all subsets of the set of committees. Accordingly, we define the Shapley value for the first model and the Aggregated Shapley value for the second, providing axiomatic characterizations for both. Further, we propose bidding mechanisms to show that the Shapley value and the Aggregated Shapley value for the class of CSG is a subgame perfect Nash equilibrium (SPNE) of the induced strategic game. Finally, we study an alternative Exchange Economy model by incorporating committees instead of commodities.

Southern Levantine societies during the Iron Age II (10th-8th centuries BCE) witnessed the formation of competing territorial polities and urban revival following a period of settlement ruralization and dwindling regional exchange economies associated with the collapse of Late Bronze Age Canaanite city-states around 1200 BCE. Recent work has revealed diverse expressions of complex political organization, state-sponsored cultic activity, and inter-polity conflicts within the region during the Iron Age II, but the impact of regular military confrontations and ensuing territorial reconfiguration on agro-pastoralist economic systems that supported these polities is unknown. Here we explore inter-polity border dynamics between the Israelite and Aramean states during periods of conflict (Iron Age IIA) and concord (Iron Age IIB) by establishing landscape-use strategies involving the most mobile element of Iron Age subsistence and production systems - domesticated sheep and goats, at Tel Hazor located in the Hula Valley, a place of direct contact between Aram and ancient Israel. Multi-stable isotopic analyses of bovid livestock teeth indicate agro-pastoralist herders grazed their animals in well-watered pastures locally near Hazor and also further afield in the Golan Heights. The continuous use of spatially diverse pasturing regimes throughout the Iron Age II suggests household-based agro-pastoralist land use transcended regional political discord. Everyday movement of herders and their flocks to distant pastures was not restricted despite conflict between the military and ruling elites of the Israelite and Aramean states, suggesting that borderlands between states were permeable.

Abstract Thermal macroeconomics (TM), an axiomatic approach to macroeconomics based on the mathematical structure of thermodynamics, is presented. Within the domain of exchange economies, TM deduces relations between aggregate properties of an economy, concerning quantities and flows of goods and money, without recourse to microeconomic foundations concerning individual economic agents. Despite the restricted scope of this initial treatment, TM has three important payoffs. 1) It provides a new and solid foundation for aspects of standard macroeconomics: the existence of market prices, the value of money, the meaning of inflation, the symmetry and negative-definiteness of the macro-Slutsky matrix, and the Le Chatelier–Samuelson principle, without relying on implausibly strong rationality assumptions over individual microeconomic agents. 2) It generates new results, including implications for money flow and trade when two or more economies are put in contact, using new concepts such as economic entropy and temperature; these concepts can be given economic interpretations as aggregate utility and the inverse marginal aggregate utility of money, respectively. 3) It holds the prospect for extensions of economic interest, such as to include production and consumption, via connection to non-equilibrium thermodynamics. More broadly, we hope that the economic analogue of entropy (governing the possible transitions between states of economic systems) may prove to be as fruitful for the social sciences as entropy has been in the natural sciences.

Late Ming court case fiction stories involving unidentifiable corpses demonstrate a spectrum of conceptions of truth and transitions within that spectrum. The material and semiotic peculiarities of these corpses, especially bodies lacking names and heads, play key roles in the fictional representation of reconstructing criminal truths and identifying bodies. Early court case fiction collections, such as Judge Bao's Hundred Cases and Longtu Court Cases, highlight Judge Bao's intellectual prowess in interpreting mystical revelations concerning the truth behind crimes and devising schemes to locate missing heads. In contrast, later narratives from early seventeenth-century vernacular fiction collections, exemplified by Three Words and Two Slaps, depict truth as emerging from the everyday activities of ordinary people, within reach of even the unvirtuous and vulgar. This shift demystifies judicial authority, redefining the locus of truth from the mystical and transcendental realm, accessible only to individuals with exceptional intellects like Bao, to the empirical domain of quotidian pursuits, specifically represented by the market and more broadly by the exchange economy. In these everyday spaces, clues to crimes and the identities of bodies are spontaneously uncovered and assembled amid various competing desires while the complex and formidable network of self-interests sometimes makes it nearly impossible to recognize the truth. These reconfigurations of the nature of truth and the agency of its discovery show the significance of the unidentifiable corpse as an epistemic and epistemological motif within the genre of court case fiction.

For a class of stochastic dynamical models of exchange economies that can be called ‘fully connected Cobb-Douglas’, the paper proves convergence of the probability distribution to an equilibrium, in total variation metric as time goes to infinity. The convergence is exponential and the equilibrium is determined uniquely by the number of agents, their ‘exponents’, and the initial amounts of money and goods in the economy.

ABSTRACT As a basis for his analysis of the capitalist system and its failures, such as unemployment, Keynes developed the concept of ‘a monetary economy of production’ which he opposed to the neoclassical interpretation of the economy that he labelled a ‘real exchange economy’. In doing so, he aimed at elaborating a theory showing how production, money and credit are closely interrelated in the economy. This approach brought about the principle of effective demand and the concept of the ‘finance motive’. There have been many developments in the capitalist system since Keynes’ time, especially in the field of finance. However, these developments grow in a specific essential environment, a monetary wage-labor system of production. Therefore, they do not challenge a fundamental, structural analysis that actually runs through the history of the economic thought and to which Keynes gave new impetus in order to explain the occurrence of economic crises.

Abstract This study analyzes exchange economies in which all players have the same utility function and all goods except money are indivisible. In this context, a necessary and sufficient condition for the existence of a competitive equilibrium is obtained based on the fact that certain associated cooperative games have a non-empty core. Based on this result, we find two conditions in the cardinal case, each of which is equivalent to the existence of an equilibrium in an economy. By introducing the $$\alpha $$ -concavity property, we obtain another sufficient (although not necessary) condition for the existence of an equilibrium. The study also proposes an algorithm to determine whether a cardinal economy has an equilibrium and, if so, to obtain the equilibrium price.

ABSTRACT We study a class of cooperative games, referred to as superadditive market games (SMG). Each SMG is characterized by a set of players, an initial endowment distribution, and a common production function that is superadditive (and meets certain regularity conditions). Due to superadditivity, players may desire to cooperate by pooling their endowments to jointly produce. We investigate kind production functions, namely production functions whose derived SMGs always have nonempty cores, regardless of initial endowment distributions. We show that a production function is kind if and only if its Walrasian core (the set of Walrasian equilibrium price vectors of a properly defined exchange economy) is always nonempty. We prove that a concave production function is kind if and only if it is homogeneous, and a convex production function is kind if and only if it satisfies a property that resembles the balancedness condition for classical cooperative games. Applying our results to newsvendor games, linear production games, and EOQ games easily reproduces several well‐known results and also generates some new results.

ABSTRACTWe study competitive equilibria in exchange economies when a continuum of goods is conflated into a finite set of commodities. The design of conflation choices affects the allocation of scarce resources among agents, by constraining trading opportunities and shifting competitive pressures. We demonstrate the consequences on relative prices, trading positions, and welfare.

The aim of the first part of this paper is to show whether a set of Proper Efficient Points and a set of Pareto Efficient Points coincide in Euclidean spaces. In the second part of the paper, we show that supporting prices, which are actually strictly positive, do exist for a large class of exchange economies. A consequence of this result is a generalized form of the Second Welfare theorem. The properties of the cones’ bases are significant for this purpose.

This paper provides a three-fold generalization of the Gale–Nikaido–Kuhn–Debreu lemma, a fundamental result for classical Walrasian general equilibrium theory. It weakens the (i) convexity assumption on the given (excess demand) correspondence, and (ii) the continuity assumption by synthesizing both the majorization and inclusion approaches, and uses these results to derive a (iii) theorem on the existence of a Walrasian equilibrium in an exchange economy with externalities, and non-ordered, non-convex, price-dependent preferences under a weaker continuity assumption that is assumed in the literature. It also highlights a trade-off between the weakened continuity and convexity assumptions.

Complementarity in matching markets and exchange economies

Abstract We consider a pure exchange economy with a finite number of goods and households. Following the path-breaking paper by Kranich, we introduce two differences with respect to the standard model: (i) each household utility function depends not only on her own consumption but also on other households’ welfare, measured by wealth; then, other-regarding preferences are based on other households opportunities; (ii) households are allowed to promise transfers to other households and the promises are bound to be honored. We provide a proof of existence of equilibria, solving several problems which are not addressed by the paper by Kranich. We present a robust example of non-existence of equilibria if the crucial assumption of an upper bound on transfers is violated. As a mathematical by-product of our analysis, we give easy-to-check conditions that ensure that commonly used constraint set-valued functions satisfy properties that are needed to apply standard existence theorems.

If we do not start our understanding of the legal phenomenon from the source – the Roman law, we will not have a correct perspective on the evolution of modern legislation. A strong argument in support of this statement is the fact that a large part of the institutions of the Napoleonic Code, which was the foundation of Romanian civil law, were taken over from the Roman law. This study aims to analyze the origin of custom as a source of law, by investigating how the sources of Roman law arose and, more particularly, evolved. Thus, in the first section, we will note that, in the history of Roman law, custom has experienced a very interesting dynamic, generated by the social and political organization in different eras: for many centuries, custom was the only form of expression of the rules of Roman law, then with the unprecedented development of the exchange economy, the law took its place. Notwithstanding, after the establishment of the Dominate, in the background of the general decline of the Roman society, custom regained its former importance. In the second section, the historical perspective will give way to the general theory of law, so that we will try to grasp the basis of custom from its features and the way in which this source of law is recognized and enshrined.

Stability and optimal double auction design for a two-sided market

Non-tâtonnement processes and planning procedures have been defined in different economic contexts, as dynamic processes to reach efficient allocations, with or without price adjustment, satisfying the property that, along the process, the utility of every agent is non-decreasing and transactions can occur, thus making a clear distinction with the study of tâtonnement processes whose goal is to reach competitive equilibria with transactions occurring only at equilibrium.In this paper, we provide sufficient conditions guaranteeing that every Pareto optimum which is preferred or indifferent to some given initial situation by every agent is accessible by a monotone efficient dynamic process. The framework considered is general enough to encompass the accessibility of Pareto optima by a non-tâtonnement barter process in an exchange economy, the neutrality of the MDP procedure in an economy with public goods, and other types of planning procedures.

Equilibria in abstract economies with a continuum of agents with discontinuous and non-ordered preferences

This paper examines equilibrium asset prices and leverage in an exchange economy populated with both retail and institutional investors. Institutional investors influence the price of the stocks they trade and are aware of the price impact of the opponent and, thus, interact strategically. Because of the price impact, institutional investors decrease their demand for stocks and lend money to the retail sector, thereby increasing leverage in the economy. The risk-free rate (equity premium) tends to be lower (higher) as compared to an economy populated by retail investors only. Retail investors' compensation for liquidity provision depends on the behavior of institutional investors and the state of the economy.