The Impact of Government Spending on Economic Diversification for the Period (2004-2019) and its Reflection on the Path of Rehabilitation of the Iraqi Economy

The research aims to measure and analyze the relationship between government spending and economic diversification in Iraq for the period (2004-2019), using the ARDL model. The research concluded that there is a long-term positive equilibrium relationship between investment spending and economic diversification in Iraq. When investment spending increases by (1%), this will lead to an increase in economic diversification by (0.23%), assuming that operating spending is stable, and the opposite happens in the case of decline. In addition to the existence of a long-term inverse equilibrium relationship between operating spending and economic diversification in Iraq, as an increase in operating spending by (1%) will lead to a decrease in economic diversification by (0.73%), assuming the stability of investment spending, and the opposite will happen in the event of decline.

Organocatalyzed Beckmann Rearrangement of Cyclohexanone Oxime by Trifluoroacetic Anhydride in a Microreactor

An efficient method for the Beckmann rearrangement of cyclohexanone oxime (CHO) catalyzed by trifluoroacetic anhydride (TFAA) is proposed in this work. The effects of experimental parameters on the reaction rate are studied, including CHO concentration, TFAA/CHO ratio, temperature, and CPL concentration. The reaction rate shows a linear relationship with TFAA/CHO ratio and reduces with the increasing of CPL concentration. Based on the experimental data and the study of in-situ FTIR, a reaction mechanism is proposed and the equilibrium relationship between CPL and TFAA is established. A rate constant model is developed and is in good agreement with the experimental results. The TFAA/TFA catalytic system allows high conversion and reaction rate compared with other organic acids.

Tooth Position and Deformation of Flexspline Assembled with Cam in Harmonic Drive Based on Force Analysis

Deformation of the flexspline is the basis of analyzing tooth trajectory and designing tooth profile. Considering the tooth influence on the position of equivalent neutral layer, a piecewise method for calculating the deformation of flexspline assembled with a cam wave generator is presented in this paper. Firstly, a mechanic model of a ring of uniform thickness in contact with a rigid cam is established. The displacements of the ring inside and outside an unknown wrapping angle are determined by the geometric constraints of the cam profile and the equilibrium relationship, respectively. Meanwhile, the wrapping angle is solved according to the boundary conditions. The assembly forces are derived to investigate the circumferential elongation and strain. Then, considering the tooth effects on the neutral layer of flexspline, the tooth is positioned on the equivalent neutral layer, which is the non-elongation layer within one gear pitch but offset from the geometric mid-layer. The equivalent neutral layer is positioned by the empirical formula of the offset ratio, which is summarized by the orthogonal simulation on finite element models of racks. Finally, finite element models of a ring-shaped and a cup-shaped flexspline assembled with elliptical cam are established to verify the effectiveness and accuracy of the piecewise method. The results show that, compared with the geometric method, the tooth positioning deviation calculated by the piecewise method can be reduced by about 70% with a more accurate deformation description from the geometric condition and mechanic condition inside and outside the wrapping angle.

SPURIOUS REGRESSION ANALYSIS ON TIME SERIES DATA FROM FACTORS AFFECTING INDONESIAN HUMAN DEVELOPMENT INDEXS IN 1990 – 2017

In a spurious regression conditions occur linear regression equations that are not stationary on the mean and variance. If the variables are not stationary, there will be cointegration, so it can be concluded that there is a long-term equilibrium relationship between the two research variables and in the short term there is a possibility of an imbalance, so to overcome it in this study using the Error Correction Model. The purpose of this study is to apply a cointegration test to see whether there is a long-term non-equilibrium relationship between the time series between the Human Development Index and life expectancy at birth, average school year for adults aged 25 years and over and gross national income per capita. The data used in this study are time series data between 1990-2017. The statistical management is carried out using Eviews 10. Based on the results obtained, it was concluded that 81.7% and it can be said that the types of independent variables included in the model are already good, because only 18.3% of the diversity of the dependent variable is influenced by the independent variables outside this research model. Keywords: spurious regression, stationary, cointegration, error correction model, equilibrium

Modeling the Grain Import Trade: A Cointegration Analysis of China’s Panel Data

In recent years, China has become the world’s largest importer of grain, and scholars have particularly examined whether China’s grain import trade presents this effect. By applying cointegration analysis to trade statistics panel data of China’s wheat, corn, rice, and soybean production and imports from January 2016 to December 2019, this paper empirically tests for the existence of the great country effect in China’s grain import trade. The results show that during the sample period, there is a long-term stable equilibrium relationship between the import volume, domestic price, and international price of the four major grains; the great country effect in the import trade of wheat and rice is not significant. The imports of corn and soybean present a great country effect to a certain extent in the short term; moreover, a change in the grain price in the international market does not lead to a change in China’s grain import volume, which shows that the great country effect in China’s grain import trade is distorted. Therefore, China should pay close attention to the impact of international factors on the fluctuation of its own food prices and enhance its ability to rationally utilize the international food market and international agricultural resources to ensure domestic food security.

Relationships between Copper Futures Markets from the Perspective of Jump Diffusion

This paper analyzes the price correlation effect between domestic and foreign copper futures contracts. The VAR-BEKK-GARCH (1,1) spillover effect model and the BN-S class non-parametric model based on the jumping perspective are used. The co-integration test shows a long-term equilibrium relationship between the three copper futures markets, and the Granger causality test shows that copper futures contracts have significant two-way spillover effects between different periods in Shanghai for New York copper and unidirectional mean spillover effects for London copper. The BEKK model shows significant bidirectional fluctuation spillover effects between the futures contracts of the Shanghai, London, and New York copper markets before the stock market crash. After the crash, Shanghai and New York copper have significant one-way fluctuation spillover effects on London copper futures contracts. There are jumps within a single market, and the number of joint jumps between markets increases with the significance level.

Analysing the relationship between CO2 emissions and GDP in China: a fractional integration and cointegration approach

This paper examines the relationship between the logarithms of carbon dioxide (CO2) emissions and real Gross Domestic Product (GDP) in China by applying fractional integration and cointegration methods. These are more general than the standard methods based on the dichotomy between stationary and non-stationary series, allow for a much wider variety of dynamic processes, and provide information about the persistence and long-memory properties of the series and thus on whether or not the effects of shocks are long-lived. The univariate results indicate that the two series are highly persistent, their orders of integration being around 2, whilst the cointegration tests (using both standard and fractional techniques) imply that there exists a long-run equilibrium relationship between the two variables in first differences, i.e. their growth rates are linked together in the long run. This suggests the need for environmental policies aimed at reducing emissions during periods of economic growth.

Measurement and Analysis of Total Local Production Effect on Investment Spending in Iraq from 1990-2018

Investment is one of the important economic activities that occupies fundamental place in the priorities of economic studies because the size of investment determines the volume of production and income and then the rate of economic growth and contributes to pushing the wheel of economic growth, so this research tries to measure the function of investment spending in the Iraqi economy during the extended period From 1990-2018, using the ARDL model, the results of this study showed that there is a long-term equilibrium relationship between income and investment spending and that investment spending depends largely on income, meaning that the relationship between investment spending and income is positive, and the marginal propensity to invest is 0.13.