---

International trade expansion and export development have been the center of attention by the economists, policy makers and the cornerstone of planning in many countries of the world. Agricultural and industrial sectors are the crucial economic sectors in every country that have a parity role in preparing food for people and industrial inputs. This article using vector error correction models considers the simultaneous effect of economic policies on agricultural and industrial exports during the years 1971 to 2005. After testing the stationery, Johansen test was used for long run estimation. Results have shown that monetary policy has positive and significant effect on industrial and agricultural exports in short run, while interest rate and government expenditures have significant inverse and direct effect on industrial and agricultural exports respectively, and exchange rate policy has the same effect on industrial and agricultural export in long-run. Finally, the strength of each variable was investigated on export. It is recommended that increasing non oil export, the real value of interest rate is determined and by rising volume of money and then investing it and improving commodity supply, inflation will decrease and therefore non oil export will increase.

---

According to trade theories, economic integration results in increasing trade and income among trade partners. This paper tries to test the major factors affecting the exports of agricultural products in ECO members using spatial econometric approach. For this purpose, the exports statistics of ECO members has been used in the form of panel data during 1992-2008. Agricultural exports function has been estimated using the Static (fixed and random effects) and Dynamic (generalized method of moments (GMM)) methods in panel data with classic and spatial econometric approaches. The estimated results indicate the existence of spatial dependence among the countries, so the using this estimation procedure is justified. GDP, Exchange rate and spatial variables (such as proximity) have positive effects and Population has negative effect on agricultural exports. Finally, it is suggested that the estimation equations should consider the proximity between the countries and with the increase in the exchange rate and GDP, increase exports in order to provide the necessary basis. Population control policies may also apply.

---

Tax evasion linked to imports is a cause for forming informal economy. Tax evasion decreases government revenue and makes restrictions in implementing economic policies. This paper investigates relationship between the tariff rate and tax evasion at the six- digit HS level on trade data of Iran and its twelve major trading partners during 2003 to 2008.  According to Bhagwati method, Tax evasion is defined as the discrepancy between the value of imports, reported by Iran, and the value of exports to Iran, reported by its trading partners. The results from estimated tax evasion models show that there is positive and significant relationship between the trading discrepancies or tax evasion and tariff rates among 27917 products. The elasticity of tax evasion with respect to tariff rates is 0.67, i.e. each one-percentage-point increase in the tariff rates raises tax evasion by 0.67 percent in case of total products. Additionally, the elasticity of tax evasion with respect to tariff rates is 0.8 for goods having tariff rates above average. In this case, tax evasion is more likely. The positive impact of tariff rate on tax evasion is not verified for goods having tariff rates lower than average.