Comparative advantage, multi-product firms and trade liberalisation : An empirical test

This paper investigates how economies of scope in multi-product firms interact with comparative advantage in determining the effect of trade liberalisation on resource reallocation, using Belgian manufacturing firm- and firm-product-level data over the period 1997-2007. We first provide evidence on industry integration induced by multi-product firms producing simultaneously in multiple industries and on the extent to which industry integration occurs between industries that have different degrees of comparative advantage. We then examine the impact of opening up trade with low-wage countries on both inter- and intra-industry resource reallocation, taking into account heterogeneity in the integration rate across sectors and industries. Our results indicate that, within more closely integrated sectors, trade liberalisation with low-wage countries leads to less reallocation from low-skill-intensity (comparative-disadvantage) industries to high-skill-intensity (comparative-advantage) industries, both in terms of employment and output. We also find that more integrated industries experience less skill upgrading after trade liberalisation with low-wage countries. Furthermore, we find that within sectors with a low integration rate, trade liberalisation with low-wage countries induces relatively more aggregate TFP and average firm output growth in comparative-advantage industries than in comparative-disadvantage industries, in line with the prediction of Bernard, Redding and Schott (2007), while the opposite is true in highly integrated sectors. Decomposition of the industry-level aggregate TFP changes reveals that the result is mainly driven by reallocation between incumbent firms within industries. Overall, the results are highly consistent with the predictions of the Song and Zhu (2010) model.trade liberalisation, industry integration, comparative advantage, firm heterogeneity, microeconomic panel data, Total Factor Productivity

Predictions of energy profile of four states in USA

In this paper, we calculate the value of the residual energy in 2001-2009 in four states by establishing Grey Prediction Model.  We use MATLAB software programming to predict the energy profile of each state for 2025 and 2050 in the absence of any policy changes

Para-particle oscillator simulations on a trapped ion quantum computer

Deformed oscillators allow for a generalization of the standard fermions and bosons, namely, for the description of para-particles. Such particles, while indiscernible in nature, can represent good candidates for descriptions of physical phenomena like topological phases of matter. Here, we report the digital quantum simulation of para-particle oscillators by mapping para-particle states to the state of a qubit register, which allow us to identify the para-particle oscillator Hamiltonian as an $XY$ model, and further digitize the system onto a universal set of gates. In both instances, the gate depth grows polynomially with the number of qubits used. To establish the validity of our results, we experimentally simulate the dynamics of para-fermions and para-bosons, demonstrating full control of para-particle oscillators on a quantum computer. Furthermore, we compare the overall performance of the digital simulation of dynamics of the driven para-Fermi oscillator to a recent analog quantum simulation result.Comment: 7 pages, 5 figures, 1 tabl

Quantum walks and Dirac cellular automata on a programmable trapped-ion quantum computer

The quantum walk formalism is a widely used and highly successful framework for modeling quantum systems, such as simulations of the Dirac equation, different dynamics in both the low and high energy regime, and for developing a wide range of quantum algorithms. Here we present the circuit-based implementation of a discrete-time quantum walk in position space on a five-qubit trapped-ion quantum processor. We encode the space of walker positions in particular multi-qubit states and program the system to operate with different quantum walk parameters, experimentally realizing a Dirac cellular automaton with tunable mass parameter. The quantum walk circuits and position state mapping scale favorably to a larger model and physical systems, allowing the implementation of any algorithm based on discrete-time quantum walks algorithm and the dynamics associated with the discretized version of the Dirac equation.Comment: 8 pages, 6 figure

Generation of Thermofield Double States and Critical Ground States with a Quantum Computer

Finite-temperature phases of many-body quantum systems are fundamental to phenomena ranging from condensed-matter physics to cosmology, yet they are generally difficult to simulate. Using an ion trap quantum computer and protocols motivated by the Quantum Approximate Optimization Algorithm (QAOA), we generate nontrivial thermal quantum states of the transverse-field Ising model (TFIM) by preparing thermofield double states at a variety of temperatures. We also prepare the critical state of the TFIM at zero temperature using quantum-classical hybrid optimization. The entanglement structure of thermofield double and critical states plays a key role in the study of black holes, and our work simulates such nontrivial structures on a quantum computer. Moreover, we find that the variational quantum circuits exhibit noise thresholds above which the lowest depth QAOA circuits provide the best results