Advertising and pricing at multiple-output firms: evidence from U.S. thrift institutions

We derive five hypotheses regarding market competition, price, and advertising from a theoretical model of a profit maximizing depository institution, and test these conjectures in a simultaneous system of deposit interest rates and advertising expenditures for a data panel of 1,867 thrift institutions that offer 13 different deposit products in 666 local markets in the U.S. between 1994 and 2000. We find some support for each of our hypotheses – branding, information, Dorfman-Steiner, structure-advertising, and structure-price – with the strength of the results often depending on the attributes of the deposit products or the characteristics of the thrifts.Advertising ; Thrift institutions

Bank imputed interest rates: unbiased estimates of offered rates?

We examine whether “imputed” interest rates obtained from bank financial statements are unbiased estimates of “offered” interest rates that the same banks report in surveys. We find evidence of a statistically significant amount of bias. However, the statistical bias that we document does not appear to be economically significant. When used as dependent variables in regression analysis, imputed rates and offered rates lead to the same policy conclusions. Our work has important methodological implications for empirical research that examines the product market competition among depository institutions.Interest rates

Analysis of two-orbital correlations in wavefunctions restricted to electron-pair states

Wavefunctions constructed from electron-pair states can accurately model strong electron correlation effects and are promising approaches especially for larger many-body systems. In this article, we analyze the nature and the type of electron correlation effects that can be captured by wavefunctions restricted to electron-pair states. We focus on the Antisymmetric Product of 1-reference orbital Geminal (AP1roG) method combined with an orbital optimization protocol presented in [Phys. Rev. B, 89, 201106(R), 2014] whose performance is assessed against electronic structures obtained form DMRG reference data. Our numerical analysis covers model systems for strong correlation: the one-dimensional Hubbard model with periodic boundary condition as well as metallic and molecular hydrogen rings. Specifically, the accuracy of AP1roG is benchmarked using the single-orbital entropy, the orbital-pair mutual information as well as the eigenvalue spectrum of the one-orbital and two-orbital reduced density matrices. Our study indicates that contributions from singly occupied states become important in the strong correlation regime which highlights the limitations of the AP1roG method. Furthermore, we examine the effect of orbital rotations within the AP1roG model on correlations between orbital pairs.Comment: 15 pages, 8 figure

The Challenge of the Commons in the Post-Socialist Era

Since the neo-liberal turn of the 1970s and the consequent failure of the state socialist experiment, the functioning of the Eastern European states has increasingly been governed by the rationality of markets. This logic has led to an erosion of the concept of the commons and, by extension, universality. The notion of then alternative but now mainstream culture creates and serves particular class interests under the banner of ’independence’ and ’freedom’, which aims not to transcend the status quo but to preserve it and the property relations on which it is based. My thesis is written as a first step to reclaim the idea of the commons, pointing to the capitalist genesis of the forms in our contemporary culture

Condition of Public Primary Schools in Terms of Emotional Social Support and Parents’ Learning Needs Parallel to This Subject

This research aims to determine the public primary schools’ conditions in terms of emotional social support and parents’ learning needs regarding this subject in the Manavgat County of Antalya City. The universe of this model which was conducted through scanning model was consisted of parents who have children attending to the public primary schools in the Manavgat County. The data was collected from the sampling set that was consisted of 384 parents. In interpretation of the collected data, frequency, percentage and chi-square methods were utilized. It was determined that almost all of the parents were in positive attitude regarding emotional support for their children. However, it was also understood that there were some parents who cannot provide sufficient support which cannot be ignored in number and they were in need in terms of emotional social support. Keywords: Emotional Support , Parental involvement, Student Achievement , Adult Educatio

Excited states in poly-diacetylene chains: A Density-matrix-renormalization-group study

We study theoretically poly-diacetylene chains diluted in their monomer matrix. We employ the density-matrix renormalization group method (DMRG) on finite chains to calculate the ground state and low-lying excitations of the corresponding Peierls--Hubbard-Ohno Hamiltonian which is characterized by the electron transfer amplitude t0 between nearest neighbors, by the electron-phonon coupling constant \alpha, by the Hubbard interaction U, and by the long-range interaction V. We treat the lattice relaxation in the adiabatic limit, i.e., we calculate the polaronic lattice distortions for each excited state. Using chains with up to 102 lattice sites, we can safely perform the extrapolation to the thermodynamic limit for the ground-state energy and conformation, the single-particle gap, and the energies of the singlet exciton, the triplet ground state, and the optical excitation of the triplet ground state. The corresponding gaps are known with high precision from experiment. We determine a coherent parameter set (t0*=2.4 eV, \alpha*=3.4 eV/\AA, U*=6 eV, V*=3 eV) from a fit of the experimental gap energies to the theoretical values which we obtain for 81 parameter points in the four dimensional search space (t0, \alpha, U, V). We identify dark in-gap states in the singlet and triplet sectors as seen in experiment. Using a fairly stiff spring constant, the length of our unit cell is about one percent larger than its experimental value.Comment: 18 pages, 13 figure

Impulzustérbeli sűrűségmátrix-renormálásicsoport-algoritmus fejlesztése és alkalmazása fermion modellekre. = Development and application of momentum space density matrix renormalization group method for fermion models

Az OTKA pályázat kutatási tervének megfelelően a négyéves időszak alatt a sűrűségmátrixos renormálásicsoport-algoritmus (DMRG) számos fejlesztését végeztük el, kiváltképpen a kvantuminformáció-elmélet (QIT) összefüggéseinek alkalmazása mellett. E két terület kapcsolatát legjobban leíró ún. összefonódottságot, mely egyben a kvantumos rendszerek alapvető tulajdonságait is megszabó mennyiség, hatékonyan alkalmaztuk spin és fermionrendszerek vizsgálatára rövid és hosszú távú kölcsönhatások figyelembevétele mellett. Kutatásaink mindezek tükrében interdiszciplináris jellegűek voltak, melyet jól tükröznek az általunk vizsgált szilárdtestfizikai, kvantumkémiai és statisztikus fizikai problémák. A numerikus vizsgálatok mellett számos esetben elvégeztük a modellek analitikus módszerekkel való közelítését is, így végső megállapításainkat az analitikus predikciók és numerikus számítások együtteseként alakítottuk ki. Fontos megjegyezni, hogy világszinten - legjobb tudomásom szerint - mindösszesen hat olyan DMRG kód létezik, mely hosszú távú kölcsönhatások kezelését is lehetővé teszi. | In the past for years we have developed the most general version of the densitymatrix-renormalization group (DMRG) method treating non local interactions and implemented various concepts of quantum information theory (QIT) in order to optimize the RG procedure. Quantum systems with short and long ranged interactions have been studied with great success. Models of such fields include mixed-stack compounds, quantum chemical systems, various spin systems in one dimensions. We have also analyzed quantum fluctuations between subsystems and defined an effective temperature to describe such effects. In addition, we have developed new methods based on the entanglement between subsystems to detect and locate quantum phase transition

Second-order Peierls transition in the spin-orbital Kumar-Heisenberg model

We add a Heisenberg interaction term $\propto\lambda$ in the one-dimensional SU(2)$\otimes$XY spin-orbital model introduced by B. Kumar. At $\lambda=0$ the spin and orbital degrees of freedom can be separated by a unitary transformation leading to an exact solution of the model. We show that a finite $\lambda>0$ leads to spontaneous dimerization of the system which in the thermodynamic limit becomes a smooth phase transition at $\lambda\to 0$, whereas it remains discontinuous within the first order perturbation approach. We present the behavior of the entanglement entropy, energy gap and dimerization order parameter in the limit of $\lambda\to 0$ confirming the critical behavior. Finally, we show the evidence of another phase transition in the Heisenberg limit, $\lambda\to\infty$, and give a qualitative analytical explanation of the observed dimerized states both in the limit of small and large $\lambda$.Comment: 11 pages, 12 figure

Simulating Strongly Correlated Quantum Systems with Tree Tensor Networks

We present a tree-tensor-network-based method to study strongly correlated systems with nonlocal interactions in higher dimensions. Although the momentum-space and quantum-chemistry versions of the density matrix renormalization group (DMRG) method have long been applied to such systems, the spatial topology of DMRG-based methods allows efficient optimizations to be carried out with respect to one spatial dimension only. Extending the matrix-product-state picture, we formulate a more general approach by allowing the local sites to be coupled to more than two neighboring auxiliary subspaces. Following Shi. et. al. [Phys. Rev. A, 74, 022320 (2006)], we treat a tree-like network ansatz with arbitrary coordination number z, where the z=2 case corresponds to the one-dimensional scheme. For this ansatz, the long-range correlation deviates from the mean-field value polynomially with distance, in contrast to the matrix-product ansatz, which deviates exponentially. The computational cost of the tree-tensor-network method is significantly smaller than that of previous DMRG-based attempts, which renormalize several blocks into a single block. In addition, we investigate the effect of unitary transformations on the local basis states and present a method for optimizing such transformations. For the 1-d interacting spinless fermion model, the optimized transformation interpolates smoothly between real space and momentum space. Calculations carried out on small quantum chemical systems support our approach

On the calculation of complete dissociation curves of closed-shell pseudo-onedimensional systems through the multireference method of increments

The Method of Increments (MoI) has been employed using a multireference approach to calculate the dissociation curve of beryllium ring-shaped clusters Be$_n$ of different sizes. Benchmarks obtained through different single and multireference methods including the ab initio Density Matrix Renormalization Group (DMRG) were used to verify the validity of the MoI truncation which showed a reliable behavior for the whole dissociation curve. Moreover we investigated the size dependence of the correlation energy at different distances in order to extrapolate the values for the periodic chain and to discuss the transition from a metal-like to a insulating-like behavior of the wave function through quantum chemical considerations