This study aims to determine and analyze the influences of world crude oil price shocks, world soybean oil prices, world CPO prices, palm oil TBS prices and the exchange rate of rupiah/US dollar towards the transmission on CPO export prices of Indonesia. This study uses quantitative analysis model with the approach of vector autogression model (VAR) which includes three main analysis tools namely Granger causality test, impulse response function (IRF) and forecast error decomposition of variance (FEDV). The variables which are used in this research are world petroleum price, world soybean oil price, CPO price of Rotterdam, CPO export price of Indonesia, fresh fruit bunch price and real exchange rate (real exchange rate). From Granger Causality test result, The price transmission process takes place the plot as follows: world crude oil prices significantly influence the CPO price of world (Rotterdam) which will significantly influence the world soybean oil prices and so on have a significant influence on the value of the real exchange rate which will influence the price of fresh fruit bunches and ultimately have a significant influence on CPO price export of Indonesia. From the estimation result of VAR model, there are significant influences of world crude oil price shocks, world soybean oil prices, world CPO prices, palm oil TBS prices and rupiah/US dollar exchange rates simultaneously to the transmission on CPO export prices of Indonesia. Based on analysis of Impulse response and variance decomposition, in the first period, one hundred percent average variability of CPO export price growth is significantly explained by the average growth of CPO export prices itself. In the subsequent period, the average variability of CPO export price growth is significantly explained by the average growth of CPO export price itself as well as other variables.
In this paper, we employed multivariate econometric analysis approach to study the relationship between taxation and income inequality in Nigeria. The study was a country-specific approach using tax and macroeconomic data from 1980 to 2011. We collected data from the Central Bank of Nigeria Publications, Federal Inland Revenue Service, World Bank and Index Mundi. We estimated the data using a combination of co-integration and error correction model. Preliminary diagnostic analysis using Ramsey RESET test, Breuch-Pagan-Godfrey, Granger causality test and Breuch-Godfrey test of serial correlation were affected to check the accuracy of our model. The preliminary analysis where favourable with no cases of serial correlation, non-normality, bi-directional causality and model misspecification. We found a negative and robust relationship between total tax revenue, total tax revenue to GDP ratio and income inequality in Nigeria with t-values of (-2.748706) and (-2.287270) and negative coefficients of (-0.007869) and (-0.512235) respectively. We found a negative but insignificant relationship between GDPPC, PCREDIT/GDP, TDT/TIT*TTR while LFP and TDT/TIT had positive but insignificant relationship with income inequality with coefficients of (0.421) and (1.243794) and t-values of (1.732565) and (1.717362) respectively.