16,048 research outputs found

    Methodological Individualism, the We-mode, and Team Reasoning

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    Raimo Tuomela is one of the pioneers of social action theory and has done as much as anyone over the last thirty years to advance the study of social action and collective intentionality. Social Ontology: Collective Intentionality and Group Agents (2013) presents the latest version of his theory and applications to a range of important social phenomena. The book covers so much ground, and so many important topics in detailed discussions, that it would impossible in a short space to do it even partial justice. In this brief note, I will concentrate on a single, though important, theme in the book, namely, the claim that we must give up methodological individualism in the social sciences and embrace instead irreducibly group notions. I wish to defend methodological individualism as up to the theoretical tasks of the social sciences while acknowledging what is distinctive about the social world and collective intentional action. Tuomela frames the question of the adequacy of methodological individualism in terms of a contrast between what he calls the I-mode and the we-mode. He argues that we-mode phenomena are not reducible to I-mode phenomena, and concludes that we must reject methodological individualism. I will argue that the irreducibility of the we-mode to the I-mode, given how the contrast is set up, does not entail the rejection of methodological individualism. In addition, I will argue that the three conditions that Tuomela places on genuine we-mode activities, the group reason, collectivity, and collective commitment conditions, if they are understood in a way that does not beg the question, can plausibly be satisfied by a reductive account. Finally, I will argue that the specific considerations advanced in the book do not give us reason to think that a reductive account cannot be adequate to the descriptive and explanatory requirements of a theory of the social worl

    The equity premium puzzle and emotional asset pricing

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    Since the equity premium as well as the risk-free rate puzzle question the concepts central to financial and economic modeling, we apply behavioral decision theory to asset pricing in view of solving these puzzles. U.S. stock market data for the period 1960-2003 and German stock market data for the period 1977-2003 show that emotional investors who act in accordance to Bell's (1985) disappointment theory - a special case of prospect theory − and additionally administer mental accounts demand a high equity premium. Furthermore, these investors reason a low risk-free rate. However, Barberis/Huang/Santos (2001) already showed that limited rational investors demand a high equity premium. But as opposed to them, our approach additionally supports dividend smoothing. --Behavioral Finance,Equity Premium Puzzle,CCAPM,Dividend Smoothing

    Frictional Unemployment on Labor Flow Networks

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    We develop an alternative theory to the aggregate matching function in which workers search for jobs through a network of firms: the labor flow network. The lack of an edge between two companies indicates the impossibility of labor flows between them due to high frictions. In equilibrium, firms' hiring behavior correlates through the network, generating highly disaggregated local unemployment. Hence, aggregation depends on the topology of the network in non-trivial ways. This theory provides new micro-foundations for the Beveridge curve, wage dispersion, and the employer-size premium. We apply our model to employer-employee matched records and find that network topologies with Pareto-distributed connections cause disproportionately large changes on aggregate unemployment under high labor supply elasticity

    Relativistic structure of one-meson and one-gluon exchange forces and the lower excitation spectrum of the Nucleon and the Delta

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    The lower excitation spectrum of the nucleon and Δ\Delta is calculated in a relativistic chiral quark model. Corrections to the baryon mass spectrum from the second order self-energy and exchange diagrams induced by pion and gluon fields are estimated in the field -theoretical framework. Convergent results for the self-energy terms are obtained when including the intermediate quark and antiquark states with a total momentum up to j=25/2j=25/2. Relativistic one-meson and color-magnetic one-gluon exchange forces are shown to generate spin 0, 1, 2, etc. operators, which couple the lower and the upper components of the two interacting valence quarks and yield reasonable matrix elements for the lower excitation spectrum of the Nucleon and Delta. The only contribution to the ground state nucleon and Δ\Delta comes from the spin 1 operators, which correspond to the exchanged pion or gluon in the l=1 orbit, thus indicating, that the both pion exchange and color-magnetic gluon exchange forces can contribute to the spin of baryons. Is is shown also that the contribution of the color-electric component of the gluon fields to the baryon spectrum is enormously large (more than 500 MeV with a value αs=0.65\alpha_s=0.65) and one needs to restrict to very small values of the strong coupling constant or to exclude completely the gluon-loop corrections to the baryon spectrum. With this restriction, the calculated spectrum reproduces the main properties of the data, however needs further contribution from the two-pion exchange and instanton induced exchange (for the nucleon sector) forces in consistence with the realistic NN-interaction models.Comment: 15 pages, 4 figures, 7 table

    Weakly disordered absorbing-state phase transitions

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    The effects of quenched disorder on nonequilibrium phase transitions in the directed percolation universality class are revisited. Using a strong-disorder energy-space renormalization group, it is shown that for any amount of disorder the critical behavior is controlled by an infinite-randomness fixed point in the universality class of the random transverse-field Ising models. The experimental relevance of our results are discussed.Comment: 4 pages, 2 eps figures; (v2) references and discussion on experiments added; (v3) published version, minor typos corrected, some side discussions dropped due to size constrain

    Scaffolding interactions with preschool children: Comparisons between Chinese mothers and teachers across different tasks

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    This study investigated how Chinese adults adjusted their scaffolding in interactions with children during problem-solving tasks. Fifty-seven 5-year-olds (from low and high socioeconomic status [SES] backgrounds) completed a playlike task (puzzle) and a school-like task (worksheet) with their mothers and teachers, respectively. Adult-child interactions were videotaped, and the analyses focused on how adults adjusted their scaffolding as a function of children's responses. Results indicated that teachers adjusted their scaffolding more appropriately than mothers, and that adults' sensitivity to children's understanding was associated with more appropriate scaffolding. Children from middle or upper SES families received more optimal scaffolding than those from lower SES families, and both mothers and teachers provided more skilled scaffolding in the school-like task than in the playlike task. Findings suggest that family SES, adults' professional training, and task characteristics, as well as adults' understanding of children's mastery, should be considered in the analysis of dyadic problem solving. © 2012 by Wayne State University Press.published_or_final_versio

    The Market Price of Aggregate Risk and the Wealth Distribution

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    We introduce limited liability in a model with a continuum of ex ante identical agents who face aggregate and idiosyncratic income risk. These agents can trade a complete menu of contingent claims, but they cannot commit and shares in a Lucas tree serve as collateral to back up their state-contingent promises. The limited liability option gives rise to a second risk factor, in addition to aggregate consumption growth risk. This liquidity risk is created by binding solvency constraints, and it is measured by the growth rate of one moment of the wealth distribution. The economy is said to experience a negative liquidity shock when this growth rate is high and a large fraction of agents faces severely binding solvency constraints. The adjustment to the Breeden-Lucas stochastic discount factor induces substantial time variation in equity risk premia that is consistent with the data at business cycle frequencies.
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