Showing 5 results for Jafari Samimi
Dr Ahmad Jafari Samimi, Saman Ghaderi, Salahaddin Ghaderi, Taha Ketabi,
Volume 4, Issue 13 (10-2013)
Abstract
The purpose of this study is to evaluate the impact of trade openness and economic globalization on employment. This study employs the Bounds test method and Autoregressive Distributed Lag(ARDL) model for Iranian economy during 1979-2009. Comparing with the other empirical studies, this study in addition to traditional index of trade liberalization as trade openness has been applied the new and more comprehensive economic globalization index as one dimension of the new KOF globalization index. This index includes the actual flows of trade such as trade, foreign direct investment and portfolio investment, and restrictions such as trade barriers and tariffs on actual flows. Also, the other control variables effective in employment such as GDP per capita, industrialization and government size has been considered. The results show a negative relationship between trade openness and employment but they show that the impact of economic globalization on employment is positive. Thus, it seems that the new economic globalization (KOF index) which is a broader comprehensive index is a better proxy of globalization.
Ahmad Jafari Samimi, Roozbeh Balounejad Nouri,
Volume 5, Issue 17 (10-2014)
Abstract
The main objective of this study was to investigate weak efficient market hypothesis of Tehran stock exchange. For this purpose, total price index, financial index, industry index and the index's top 50 companies data for the period 2013:7-2009:5 daily basis as well as data on prices and yields for the period 2013:2 - 2000:3 are applied on a monthly basis. In this study, the hypothesis of the poor performance of the Tehran stock exchange, using wavelets and fractional Brownian motion is investigated. The results show the aforementioned hypotheses are rejected.
Ahmad Jafari Samimi, Roozbeh Balounejad Nouri,
Volume 6, Issue 21 (10-2015)
Abstract
Given the importance and role of capital markets in the economy, its characteristics have been regarded by researchers in this field. Hence, the main purpose of the present study is testing the existence of multiple price bubbles in Tehran stock market. For this purpose, the monthly data on the total price index and price-dividend ratio for periods 2000 – 2013 has been used. In this study generalized supremum Augmented Dickey – Fuller test, which has been recently introduced, is used due to critical review of conventional methods of testing the bubbles and also the possibility of a multiple bubble in time series. In addition to the testing of multiple Bubbles, with using this method there is the possibility of determining their period of creation and decay. The results showed that in the period under review, in the period 2003:3 - 2003:5 and 2004:12 - 2005:7 hypotheses price bubble in the stock market is confirmed.
Ali Akbar Bajelan, Saeed Karimi Potanlar, Ahmad Jafari Samimi,
Volume 10, Issue 35 (3-2019)
Abstract
The purpose of current paper is to survey the asymmetric effects of inflation's positive and negative shocks on inflation uncertainty in short-run and long-run. For this end, first, the Ball model (1992) has been extended through the decomposition of inflation shocks to money demand's positive and negative shocks and money supply's positive and negative shocks. Then, through using nonlinear autoregressive distribution lag model and time series data of Iranian economy from 1978 to 2017 the positive and negative effects of inflation on inflation uncertainty, which is from the exponential generalized autoregressive conditional heteroskedasticity model, has been analyzed. The results of the study show that the effects of the inflation's positive shocks on inflation uncertainty in short-run and long-run are positive and significant. In contrast, the negative shocks have not any effects on inflation uncertainty in short-run and long-run. In other words, the rise in inflation causes an increase in inflation uncertainty in Iran; whereas, decrease in inflation has not had effects on inflation uncertainty.
Mojtaba Khodam, Mohsen Nosratian Nasab, Ahmad Jafari Samimi,
Volume 12, Issue 44 (7-2021)
Abstract
Considering the challenges related to estimating and forecasting the expected Shortfall dynamically and with a semi-parametric approach, in this study, providing a general framework, dynamic semi-parametric models in forecasting Expected Shortfall in Tehran Stock Exchange be introduced and evaluated. In this regard, the data of the period 2008.12.04-2020.08.26 and Generalized Autoregressive Score (GAS) approach are used to introducing dynamic semi-parametric models (GAS-2F, GAS-1F, GARCH-FZ and hybrid). Then expected Shortfall (ES) in Tehran Stock Exchange be estimated and forecasting performance of these models are compared with traditional models in this field, including GARCH models and rolling window models based on backtesting their results. The results of this study indicate better performance of dynamic semi-parametric models in forecasting the expected Shortfall (ES) than competing models. In addition, the GAS-1F model has shown the best performance among all models.
