Non-cooperative Behavior Research Articles

Equilibrium unfolding of proteins monitored by electrospray ionization mass spectrometry: distinguishing two-state from multi-state transitions.

The acetic acid-induced unfolding of cytochrome c (cyt c) and apomyoglobin (aMb) are studied under equilibrium conditions by electrospray ionization (ESI) mass spectrometry (MS). The folding states of the proteins in solution are monitored by the charge state distributions that they produce during ESI. A tightly folded protein shows lower charge states than the same protein in an unfolded conformation. The ESI-MS data presented in this study show that during the denaturation of cyt c, only two distinct charge state distributions are observed. These can be attributed to the native and to the acid-unfolded conformation, respectively. In the transition region where the folded and the unfolded conformation are both present in solution, these two distributions are observed simultaneously, thus giving rise to a bimodal ESI mass spectrum. These data reflect a highly cooperative (two state) folding behavior. In contrast, the acid-induced unfolding of aMb is accompanied by gradual shifts in the maxima of the observed charge state distribution. This indicates a non-cooperative unfolding behavior involving multiple protein conformations. The observations made here suggest that ESI-MS might be a general method for assessing the cooperativity of protein unfolding transitions. This study also addresses the issue of 'secondary' solvent effects for ESI-MS studies on the acid-induced unfolding of proteins. These effects influence the ESI charge state distribution without being related to conformational changes of the protein in solution and could potentially complicate the interpretation of ESI mass spectra. Data obtained for bovine pancreatic trypsin inhibitor and ubiquitin indicate that secondary solvent effects influence the observed charge state distributions only to a very minor extent between pH 8.5 and 2.5.

Rethinking the Notion of Reciprocal Exchange in International Negotiation: Sino-American Relations, 1969–1997

AbstractIntuition takes us only so far in understanding the particular obligations that states presume in reciprocity relationships. As a result, we know fairly little about who owes precisely what to whom, and on what schedule. Two polar patterns, specific and diffuse reciprocity, have been identified that answer these questions. Yet in some relationships, the parties do not expect one-for-one exchanges (the pattern that characterizes specific reciprocity) or exchanges very loosely matched in terms of both equivalence and value (the pattern that characterizes diffuse reciprocity). In this article, we develop a general explanation of the causes and consequences of reciprocal exchange. We argue that actors' expectations about time horizons and the degree to which they anticipate a reliable stream of benefits from a relationship drive their assumptions about the value and timing of trades, creating four distinct patterns of reciprocal exchange. This argument helps us understand how actors perceive their obligations, others' obligations, and thus, the content of cooperative and noncooperative behavior. Differentiating these types also allows us to infer what is likely to serve as effective bargaining leverage across situations. We use this argument to interpret the past three decades of Sino-American relations. While there is a large literature on this relationship, our argument illuminates the sources and consequences of various sets of expectations by each party over time.

The Two Faces of Adam Smith

Adam Smith's two major works are based on apparently contradictory themes in human nature: noncooperative self-interest and other-regarding sympathy. These views are not contradictory if we distinguish impersonal market exchange and personal exchange. Noncooperative behavior in the former maximizes the gains from exchange, the basis of specialization and wealth creation. Cooperative behavior in personal exchange is based on reciprocity-trading gifts, favors, and assistance across time-which maximizes the gains from social exchange. That people can be both cooperative and noncooperative is corroborated in laboratory experiments and is postulated to stem from a self-interested propensity for exchange in markets and friendships.

Fast events in protein folding: relaxation dynamics and structure of the I form of apomyoglobin.

The fast relaxation dynamics of the acid destabilized I form of apomyoglobin (pH* 3, 0.15 M NaCl; apoMb-I) following a laser-induced temperature-jump have been probed using time-resolved infrared spectroscopy. Only a fast, single exponential phase is observed (bleach centered at v = 1633 cm-1 and transient absorbance at 1666 cm-1) with relaxation times of 38 ns at 30 degrees C and 36 ns at 57 degrees C; no additional slow (microsecond) phase is observed as previously found in the native form of apomyoglobin. Folding times of approximately 66 ns are derived from the observed rates based on a simple two-state model. The equilibrium melting of the 1633 cm-1 component shows noncooperative linear behavior over the temperature range studied (10-60 degrees C). The low amide I' frequency, the fast relaxation dynamics, and the noncooperative melting behavior are characteristic of isolated solvated helix. The analysis of the amide-I' band reveals another major component at 1650 cm-1 assigned to native-like structure stabilized by tertiary contacts involving the AGH core, which does not show dynamic or static melting under our conditions. ApoMb-I has generally been taken to be a "molten globule" species. The present results indicate a heterogeneous structure consisting of separate regions of native-like unit(s), solvated helices, and disordered coil, excluding a homogeneous molten globule as a model for apoMb-I. From the current studies and other results, a detailed model of the folding of apomyoglobin is presented.

Illusory Correlations in Patient Stereotyping

Two experiments document one basis of patient stereotyping: the relative frequency of people's contact with medical patients. Experiment 1 demonstrated that illusory correlations formed based on the infrequency of target patients and their non-cooperative behaviors. Participants read about two groups of patients with two similar diseases (labelled A and B). One group appeared less often than the other and performed fewer non-cooperative behaviors; however, the proportion of non-cooperative and cooperative behaviors was the same for both groups. Participants overestimated the number of non-cooperative behaviors performed by the infrequently appearing group, evaluated the group negatively and believed that these patients would be unlikely to cooperate in the future. Experiment 2 attempted to address the relationship between illusory correlations and memory for the infrequent group's non-cooperative behaviors. Implications for how people perceive medical non-adherence in patients with stigmatized medical conditions were discussed.

Bidder Collusion at Forest Service Timber Sales

Allegations of Bidder collusion at Forest Service timber sales in the Pacific Northwest were common in the 1970s. Of course, prices may be low for reasons other than collusion. We formulate an empirical model that allows for both bidder collusion and supply effects and in which we control for demand conditions. Noncooperative behavior in which a single unit is sold (the standard auction model) is a special case: it is found to be definitively outperformed by a model of collusion. We also find that supply effects are dominated by collusion in determining the winning bids in the market.

Recombinant [Phe(beta)63]hemoglobin shows rapid oxidation of the beta chains and low-affinity, non-cooperative oxygen binding to the alpha subunits.

We have engineered alpha2beta2 [Phe63]hemoglobin by changing the highly conserved distal histidine of the beta chains to a phenylalanine. The mutant tetramer binds four high-affinity ligands, such as CO or NO, to the ferrous form, or CN to the oxidized iron; however, it binds only two low-affinity ligands, oxygen and azide. The absorption spectrum of the ferrous deoxy or ferric forms are not normal, displaying an enhanced absorption of the visible band near 560 nm. Half of the autooxidation process, attributed to the mutated beta subunits, is over 1000-fold faster than for Hb A. The mutant Hb exhibits non-cooperative binding of two oxygens with an affinity about fivefold lower than those of HbA valency hybrids (alpha met beta)2. Functional properties of this mutant Hb resemble those of Hb Saskatoon ([Tyr63]Hb) [Suzuki, T., Hayashi, A., Shimizu, A. & Yamamura, Y. (1966) Biochim. Biophys. Acta 127, 280-282]. Flash-photolysis experiments also indicate non-cooperative behaviour: the CO-recombination kinetics were independent of the fraction dissociated. Furthermore, the amplitude of the CO bimolecular phase was the same for the (alpha(CO)metbeta)2 valency hybrid or the (alphaCO betaCO)2 form, suggesting mainly geminate CO-recombination kinetics to the beta chains. EPR and Resonance Raman spectra did not show evidence for a hemichrome, normally considered as a six-coordinated iron with low-spin character. The EPR and resonance Raman spectra for the mutated beta subunits demonstrate the presence of a high-spin compound in the ferric and deoxy ferrous forms. In particular, the ferrous mutated beta subunits are penta-coordinated. The abnormal absorption spectra are possibly due to an interaction between the porphyrin and the phenyl ring in the distal position rather than to direct binding to the iron.

Achieving network optima using Stackelberg routing strategies

In noncooperative networks users make control decisions that optimize their individual performance objectives. Nash equilibria characterize the operating points of such networks. Nash equilibria are generically inefficient and exhibit suboptimal network performance. Focusing on routing, a methodology is devised for overcoming this deficiency, through the intervention of the network manager. The manager controls part of the network flow, is aware of the noncooperative behavior of the users and performs its routing aiming at improving the overall system performance. The existence of maximally efficient strategies for the manager, i.e., strategies that drive the system into the global network optimum, is investigated. A maximally efficient strategy of the manager not only optimizes the overall performance of the network, but also induces an operating point that is efficient with respect to the performance of the individual users (Pareto efficiency). Necessary and sufficient conditions for the existence of a maximally efficient strategy are derived, and it is shown that they are met in many cases of practical interest. The maximally efficient strategy is shown to be unique and it is specified explicitly.

Game theory and reciprocity in some extensive form experimental games.

We examine decision making in two-person extensive form game trees using nine treatments that vary matching protocol, payoffs, and payoff information. Our objective is to establish replicable principles of cooperative versus noncooperative behavior that involve the use of signaling, reciprocity, and backward induction strategies, depending on the availability of dominated direct punishing strategies and the probability of repeated interaction with the same partner. Contrary to the predictions of game theory, we find substantial support for cooperation under complete information even in various single-play treatments.

Recurrent High Inflation and Stabilization: A Dynamic Game

We analyze the dynamics of inflation that arise from fiscal deficits caused by the noncooperative behavior of interest groups. The state variable is the degree of financial adaptation, a proxy for the share of wealth agents hold in alternatives to domestic currency. As financial adaptation becomes widespread, the costs of financing a given budget deficit rise. In this context, there can be fully rational cycles of increasing inflation and financial adaptation, followed by stabilization and remonetization. The model seems applicable to the experience of many Latin American countries. Many Latin American countries have suffered from high and variable inflation rates. This variability can be characterized by frequent attempts to stabilize which succeed in rapidly bringing inflation down but which are gradually abandoned. The resulting price patterns for Argentina and Brazil during the 1980s are shown in Figure 1. Most of these stabilization efforts are supported by the population at their inception, but support eventually dwindles away. In this paper, we provide a model in which this pattern develops and is repeated through time. A possible hypothesis is that governments (societies) have a number of different goals. For instance, there may be demands on the government for redistribution, which can easily be met by printing money. At low inflation, those goals/demands become salient and policies are implemented that sooner or later lead to high inflation. At that stage the inflation problem becomes salient and stabilization is attempted. In this paper, we take a political economy approach to the question of inflation, trying to explain the observed patterns within an individually optimizing setting. We

Existence and Properties of Equilibria for a Dynamic Game on Productive Assets

We consider a model in which two agents share access to the same stock of a productive asset and study the implications of non-cooperative consumption behavior over time. Under standard assumptions on the production function we construct infinitely many Nash equilibria, all of which consist of stationary Markovian strategies. These equilibria result in overconsumption so that the uniquely determined long-run asset stock is too low as compared to the cooperative solution. However, in the limit as the discount rate becomes sufficiently small the stead states generated by the Markovian Nash equilibria converge to the efficient steady state.Journal of Economic LiteratureClassification Numbers: C73, O41, Q22.

The hybrid equilibria and core selection in exchange economies with externalities

This paper introduces a hybrid equilibrium concept that combines the elements of cooperative and non-cooperative behaviors in an exchange economy with externalities. For a fixed coalition structure (or a partition of traders), the hybrid equilibrium is a price and consumption bundle such that each coalition chooses a core solution from its budget set and the consumption bundles are feasible. It becomes the competitive equilibrium when the position is the finest, and it selects a core allocation when the partition is the coarsest. The paper provides sufficient conditions for the existence of a hybrid equilibrium for any coalition structure.

Regulation of multinational firms with two active governments: A common agency approach

When a government agency imposes cost-based taxes/ regulations on a multinational with private cost information, it may initiate countervailing regulations by another of the governments with which the multinational interacts. We analyze the problem of optimal regulation of a multinational under incomplete cost information (via trade taxes) by multiple governments as a problem of common agency with adverse selection. By focusing on the game played by the competing governments we characterize the equilibrium trade taxes and show that the non-cooperative behavior of the governments not only reduces aggregate national welfare but also reduces firm profits.

Is there room for convergence in the E.C.?

In this paper we develop a theoretical framework which makes it possible to analyze several aspects of convergence between E.C. countries. The analysis is done in a dynamic game context, where countries, apart from minimizing individual cost functions, minimize cooperatively a convergence function, which represents the convergence conditions as elaborated in the Maastricht Treaty in 1991. This aspect of convergence is modeled as a dynamic constraint on the individual cost functions. We show that if countries' own welfare is their primary interest (and convergence becomes secondary) the maximum degree of convergence is completely determined by the non-cooperative outcome of the game. The framework is illustrated in a theoretical example. The example shows that costs involved to obtain convergence can differ substantially between countries and that, ultimately, these high costs for some countries will result in non-cooperative behaviour. Furthermore, it is shown that a small deviation from a Pareto optimal solution can increase convergence considerably. An algorithm is devised to obtain solutions of the game which are politically more feasible than the Nash bargaining solution and improve on the non-cooperative solution.

Architecting noncooperative networks

In noncooperative networks users make control decisions that optimize their individual performance measure. Focusing on routing, two methodologies for architecting noncooperative networks are devised, that improve the overall network performance. These methodologies are motivated by problem settings arising in the provisioning and the run time phases of the network. For either phase, Nash equilibria characterize the operating point of the network. The goal in the provisioning phase is to allocate link capacities that lead to systemwide efficient Nash equilibria. The solution of such design problems is, in general, counterintuitive, since adding link capacity might lead to degradation of user performance. For systems of parallel links, it is shown that such paradoxes cannot occur and that the optimal solution coincides with the solution in the single-user case. Extensions to general network topologies are derived. During the run time phase, a manager controls the routing of part of the network flow. The manager is aware of the noncooperative behavior of the users and makes its routing decisions based on this information while aiming at improving the overall system performance. We obtain necessary and sufficient conditions for enforcing an equilibrium that coincides with the global network optimum, and indicate that these conditions are met in many cases of interest. >

The New Regionalism and the Threat of Protectionism

This paper relies on game theory concepts to discuss both the incentives that lead countries to form themselves into trading blocs and what the relations between these blocs are likely to be. It argues that regional integration arrangements (RIAs) can work better as precommitment devices to internally cooperative policies than as global rules because they create a denser network or interlinked targets. The losses for a participant ostracized (or disciplined) from his bloc are therefore more immediate and tangible. The hope that RIAs can pave the way for global free trade, however, is unrealistic. As RIAs enlarge they maybe better off by exerting market power against outsiders rather than following a globally cooperative path. Interbloc trade relations will ultimately depend on how effective special interest groups are in distorting bloc-wide trade policies to suit their particular interests. These results highlight the importance of a multilateral trading system able to inhibit noncooperative behavior among trade blocs. J. Japan Int. Econ., Dec. 1994, 8(4), pp. 388–421. University of Strathclyde, Glasgow, Scotland, and Department of Economics, Princeton University, Princeton, New Jersey 08544-1021; International Trade Division, International Economics Department, World Bank, Washington, DC.

Monetary policy in interdependent economies: A game theoretic approach Matthew B. Canzoneri and Dale W. Henderson MIT Press, 1991, 133 pp.

This article reviews the recent book by Matthew Canzoneri and Dale Henderson on international monetary policy. The review discusses the basic model used by the authors to illustrate the welfare losses that arise as a result of non-cooperative behavior and the proposed solutions for moving closer to the socially optimal cooperative solutions. The proposed solutions are then examined in detail and the reviewer asks whether these solutions accurately describe the way he believes cooperation has occurred in the last two decades. Finally, this work is compared to recent research on policy cooperation that does not have game-theoretic foundations.

Paternalistic Preferences, Interpersonal Transfers and Reciprocity

Anthropologists since Bronislaw Malinowski [20] and Marcel Mauss [21] have observed that reciprocity is the primary defining characteristic of voluntary interpersonal transfers. While this perspective developed from observation of behaviors in exotic societies (e.g., the kula ring of Eastern New Guinea and the potlatch of the Kwakiutl tribe of the Pacific Northwest), contemporary observers find reciprocity to be an important feature of interpersonal transfers in modern societies' as well [7; 13; 14]. Sociologists such as Alvin Gouldner [17] and Claude Levi-Strauss [19] have given reciprocity the status of a social norm. Members of society are held to have a three-part obligation: to give gifts; to accept gifts; and to respond to a gift with a gift in return. In this literature, gift exchange serves to establish, perpetuate and define social relationships. Robert Sugden [25] suggests that social conventions and norms enable people to coordinate their behavior in the face of multiple Nash equilibria, where there is no uniquely rational choice and hence rationality alone is insufficient for decision-making. The purpose of this note is to demonstrate, by means of an example, how the norm of reciprocity can play this role in supporting transfers as the equilibrium of non-cooperative behavior. The example is based on the paternalistic preferences model that Robert Pollak [22] proposed as an extension of Gary Becker's [6] model of altruism in the family. Where Becker assumes that children's utility levels enter as arguments in their parents' utility function, Pollak assumes that in addition children's levels of consumption of certain goods directly affect parents' utility.2 Thus, Becker assumes that parental utility has the form UP(CP, Ui(Ci), Uj(CJ)), where UP, Ui, and Uj denote the utility functions of the parent and children i and j respectively, and CP, Ci and C' denote their respective consumption vectors. Pollak assumes instead that parental utility is given by UP (CP, Ci, Cj, Ui(Ci), Uj (C)), where the derivatives of UP with respect to the various elements of C' and Cj differ. This explains why intergenerational transfers within families are often tied to the children's consumption of particular goods or even take the form of in-kind transfers to the

Ion exchange systems in proton-metal reactions with algal cell walls

Abstract Algal cell walls contain acidic polysaccharides, e.g. alginic acid in many marine species, and in pectin fresh-water species. At neutral pH these provide anionic sites which bind ionically to metals, and acidification releases metals when covalent bonds to H are made. Added Cu releases an equivalent amount of Ca, Mg, H from Vaucheria, and protonated amines also displace metals. Interestingly, diamines, which function as efficient growth promoters, are sorbed more strongly than monoamines based on Langmuir adsorption constants. Sorption of Pb and Cd on Rhizoclonium from the solid hydroxides releases Na, Ca, Mg from the alga and OH from the hydroxide in essentially stoichiometric amounts. Sorbed heavy, metals can be removed by precipitation of the sulfide (Cd), hydroxide (Cm AI, and Pb), or as an EDTA complex (Pb) in ion exchange processes. Values of ion exchange constants for displacement of Ca by Mg, Zn, Cd, Pb, and Cu on Vaucheria are independent of pH and increase with the (charge)2/radius of metal ions, as also observed for K and AI. These results indicate a non-cooperative behavior of anionic sites which interact with these metals by electrostatic attractions. Rates of metal desorption and ion exchange constants with alginates as model systems were also investigated.

Equilibrium Cooperation in Three-Person, Choice-of-Partner Games

The experiment involves three-person games in which one player can choose which of two others to "do business with." The ability of the chooser to switch away from a defecting partner in a subsequent stage constitutes a salient action that may be used to punish static, noncooperative play. In this manner, cooperative outcomes that are not Nash equilibria in stage games can be supported by noncooperative behavior in a multistage game. As predicted by theory, cooperation rates are low in baseline single-stage games. Cooperation rates, however, are much higher in a 10-stage version of the game. Journal of Economic Literature Classification Numbers: C72, C92.