63 research outputs found

    CEO Wrongdoing: A Review of Pressure, Opportunity, and Rationalization

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    Wrongdoing, and specifically that which is committed by top executives, has attracted scholars for decades for a number of reasons. Among them, the consequences of wrongdoing are widespread for organizations and the people in and around them. Due to the vast array of consequences, there continues to be new questions and additional scholarly attempts to uncover why it occurs. In this review, we build upon previous efforts to synthesize the body of literature regarding the antecedents of CEO wrongdoing utilizing a framework that sheds light on the status of the literature and where unanswered questions remain. We apply the Fraud Triangle, a framework drawn from the accounting literature, to derive conclusions about what we know about the pressures faced by CEOs, the opportunities afforded to CEOs to commit wrongdoing, and contributing factors to a CEO's ability to rationalize misbehavior. We organize the literature on these conceptual antecedents of CEO wrongdoing around internal (e.g., compensation structure and organizational culture) and external (e.g., shareholder pressure and social aspirations) forces. In doing so, we integrate findings from a variety of disciplines (i.e., accounting, finance, and sociology) but remain focused on management scholarship since the last review of organizational wrongdoing to provide an updated state of the literature. This review offers a clear framework and a common language;it highlights gaps in the literature and specific directions for future research with the ultimate goal of understanding why CEOs engage in wrongdoing

    Realistic description of electron-energy loss spectroscopy for One-Dimensional Sr2_2CuO3_3

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    We investigate the electron-energy loss spectrum of one-dimensional undoped CuO3_{3} chains within an extended multi-band Hubbard model and an extended one-band Hubbard model, using the standard Lanczos algorithm. Short-range intersite Coulomb interactions are explicitly included in these models, and long-range interactions are treated in random-phase approximation. The results for the multi-band model with standard parameter values agree very well with experimental spectra of Sr2_{2}CuO3_{3}. In particular, the width of the main structure is correctly reproduced for all values of momentum transfer. It is shown for both models that intersite Coulomb interactions mainly lead to an energy shift of the spectra. We find no evidence for enhanced intersite interactions in Sr2_{2}CuO3_{3}.Comment: 4 pages, 4 figure

    Dispersion of the dielectric function of a charge-transfer insulator

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    We study the problem of dielectric response in the strong coupling regime of a charge transfer insulator. The frequency and wave number dependence of the dielectric function ϵ(q,ω)\epsilon ({\bf q},\omega) and its inverse ϵ−1(q,ω)\epsilon ^{-1}({\bf q},\omega) is the main object of consideration. We show that the problem, in general, cannot be reduced to a calculation within the Hubbard model, which takes into account only a restricted number of electronic states near the Fermi energy. The contribution of the rest of the system to the longitudinal response (i.e. to ϵ−1(q,ω)\epsilon ^{-1}({\bf q},\omega)) is essential for the whole frequency range. With the use of the spectral representation of the two-particle Green's function we show that the problem may be divided into two parts: into the contributions of the weakly correlated and the Hubbard subsystems. For the latter we propose an approach that starts from the correlated paramagnetic ground state with strong antiferromagnetic fluctuations. We obtain a set of coupled equations of motion for the two-particle Green's function that may be solved by means of the projection technique. The solution is expressed by a two particle basis that includes the excitonic states with electron and hole separated at various distances. We apply our method to the multiband Hubbard (Emery) model that describes layered cuprates. We show that strongly dispersive branches exist in the excitonic spectrum of the 'minimal' Emery model (1/Ud=Up=tpp=01/U_d=U_p=t_{pp}=0) and consider the dependence of the spectrum on finite oxygen hopping tppt_{pp} and on-site repulsion UpU_p. The relationship of our calculations to electron energy loss spectroscopy is discussed.Comment: 22 pages, 5 figure

    One-dimensional dynamics of the d-electrons in α′\alpha'-NaV2_{2}O5_{5}

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    We have studied the electronic properties of the ladder compound α′\alpha'-NaV2_{2}O5_{5}, adopting a joint experimental and theoretical approach. The momentum-dependent loss function was measured using electron energy-loss spectroscopy in transmission. The optical conductivity derived from the loss function by a Kramers-Kronig analysis agrees well with our results from LSDA+U band-structure calculations upon application of an antiferromagnetic alignment of the V~3dxyd_{xy} spins along the legs and an on-site Coulomb interaction U of between 2 and 3 eV. The decomposition of the calculated optical conductivity into contributions from transitions between selected energy regions of the DOS reveals the origin of the observed anisotropy of the optical conductivity. In addition, we have investigated the plasmon excitations related to transitions between the vanadium states within an effective 16 site vanadium cluster model. Good agreement between the theoretical and experimental loss function was obtained using the hopping parameters derived from the tight binding fit to the band-structure and moderate Coulomb interactions between the electrons within the ab plane.Comment: 23 pages, 8 figures; submitted to PR
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