Sharif Digital Repository

Why trade liberalizations increase the skill premium? To explain this empirical evidence that is in contrast with the conventional theory of Heckscher-Ohlin, I build up a general equilibrium micro-founded heterogeneous-firm model of international trade where firms make decisions on their division of labor, and firms’ skill-intensities are endogenously determined. I show why the exporters are generally more productive and skill intensive and how trade cost reductions induce more productive firms to choose a higher degree of labor specialization, become more skill intensive and start to export. I further demonstrate how such internal horizontal organizational changes, after a trade cost... 

To what extent can a short-term decline in the output of a small open economy be explained by trade barriers? To answer this, we extend the Business Cycle Accounting method of Chari et al. (2007) to a small open economy model. We include an additional time-varying wedge to model financial trade frictions caused by barriers on imports. International sanctions on Iran provide an empirical opportunity to apply this method to data on Iran's recession in 2012-13. The results indicate that efficiency and investment wedges account for most of the fluctuations in aggregate variables during the sanctions, and trade barriers had little contemporaneous explanatory power. The effect of oil boycotts... 

To what extent can a short-term decline in the output of a small open economy be explained by trade barriers? To answer this, we extend the Business Cycle Accounting method of Chari et al. (2007) to a small open economy model. We include an additional time-varying wedge to model financial trade frictions caused by barriers on imports. International sanctions on Iran provide an empirical opportunity to apply this method to data on Iran's recession in 2012-13. The results indicate that efficiency and investment wedges account for most of the fluctuations in aggregate variables during the sanctions, and trade barriers had little contemporaneous explanatory power. The effect of oil boycotts... 

This paper presents a small open economy, dynamic general equilibrium model with cash-in advance constraint and a currency attack to explain the dynamic effects of changes in trade barriers in the short and long run. The model is calibrated using data on macroeconomic variables in Iran's economy from 1990 to 2013 to identify and analyze the effects of barriers imposed on trade. We analyze the effects of counterfactual fiscal, monetary and exchange rate policies in response to trade barriers and show how the economy would respond in different time horizons. We also evaluate the effects of eliminating each of the factors causing this stagflation. Our findings show that the short-term drop in... 

In this article, we investigate the impact of trade openness on labour force participation rate. We use tariff rate as the main indicator of trade openness and we employ the number of regional trade agreements and the average tariff rate in the neighbours’ countries as instrumental variables to diminish the endogeneity problem of the tariff rate. We find that trade openness increases the participation rate which is economically and statistically significant. The results show that this correlation is robust under controlling for different variables and using various specifications. We find that 10 percentage point increase in tariff rate lowers the participation rate by 4–6 percentage point... 

Using the Fractal Geometry in Signal processing has been extended nowadays [1]. They have found several applications in signal detection and recognitions. They use the chaotic feature of the noise and clutter and try to distinguish between the noise, clutter and the desired target [2] [3]. Recent works show that lots of clutters like sea and ground clutters have fractal behavior so this kind of approach to the signal detection has been extended these days[3][4]. In this paper we have used the Box-Counts of a signal rather than the Fractal dimension of a signal as will be defined later in the text. By applying the new defined concept we have developed different methods of signal detection. We... 

Using the unique pricing method of Tapsi, the second-largest ride-hailing company in Iran, we estimate the price elasticity of demand for Tapsi rides. Tapsi mechanically divides Tehran, the largest city of Iran, into 256 regions using a 16 × 16 matrix of straight lines, to implement surge pricing in response to excess regional demand or supply. Surge multiplier works for all ride requests within each region, independent of supply and demand in neighboring regions or rides characteristics. We exploit this sharp discontinuity in pricing by running a regression discontinuity to estimate the causal effect of the price change on the number of ride requests, i.e., price elasticity of demand. Using... 

Using the unique pricing method of Tapsi, the second-largest ride-hailing company in Iran, we estimate the price elasticity of demand for Tapsi rides. Tapsi mechanically divides Tehran, the largest city of Iran, into 256 regions using a 16 × 16 matrix of straight lines, to implement surge pricing in response to excess regional demand or supply. Surge multiplier works for all ride requests within each region, independent of supply and demand in neighboring regions or rides characteristics. We exploit this sharp discontinuity in pricing by running a regression discontinuity to estimate the causal effect of the price change on the number of ride requests, i.e., price elasticity of demand. Using...