Long term monopoly in the telecommunications sector can make to the welfare costs. In this paper using 30 provincial telecommunication company that supply fixed telephony in Iran during period 2004-2008 we estimate welfare loses. Study concludes that estimated welfare loses (45 to 63 percent of sale value) comparing other research is so high and continuing to raise in study period and therefore proposes regulation for this sector.

The aim of this study is to estimate the fluid milk demand function and calculation of Welfare Loss due to monopoly power in milk production industry in 13 provinces from 2001 to 2005(65 observation). In this study, after Estimation of milk demand function, Welfare Loss due to monopoly power in fluid milk market via SCP model was calculated. The results revealed that milk price had negative effect on milk demand. On the other hand, price of substituted potables and advertisement costs had positive impact on fluid milk demand. Results indicate that welfare loss during 2001- 2003 is increasing but from 2003 to 2005 has had a decreasing trend.

Level of groundwater is decreased which is mainly because, withdrawal of groundwater is increased, because of lack of right management. Economics of rural based farming and farming is dependent of water so decreasing of groundwater effects social welfare. In this study decrease of welfare measure by reason of reduction of groundwater level considered. This study investigated the impact of withdrawal on a measure of social welfare with using econometric model. Production function and social model was estimated. Data were obtained for semi-deep and deep well, so 130 farmers were chosen at 2007-2008 in Firoozabad plain with a random sampling method. Results show that value of marginal product is more than cost of withdrawal of water. Social welfare decrease 924110 and 431210 tomans by decreasing of one meter in level of groundwater for semi-deep and deep well, respectively. The result indicated that loss of social welfare is estimated to be 8.1 and 3.8 tomans per cubic metric reduction in groundwater for semi-deep and deep well, respectively.

Purpose: To report visual and anatomical outcome of flap loss after LASIK surgery for correction of high myopia. Materials & Methods: Retrospective evaluation of flap loss in two eyes of two patients, a rare complication of LASIK Surgery. Case No. 1: 27 y/o woman with Ref. OD -9.75; 2.75*177 VA. CC: 20/60 KR OD: 41.86*77 39.86 * 168 & partial amblyopia due to anisometropia. Case No. 2: 38 y/o woman with Ref OD. -9.50 1.0*177 VA CC: 20/30 KR OD: 42.06*77 40.99 * 167. Results: In both patients during LASIK surgery free cap complication occurred and after Laser therapy free cap positioned over the stromal bed, but the next day after operation flaps were lost. For case NO.1only medical management performed and after 4.5 years F/U cornea has 2° central haziness. For case NO.2 another corneal flap from donor globe cut and sutured with Nylon 10/0 and after 18 months F/U cornea is clear. Conclusion: In patients with flat keratometry less than 41.0 Diopter rate of free cap are high and after laser therapy for high myopia the keratometry became more flat. If surgeon doesn't suture flap the rate of flap loss increase so for prevent of corneal haziness and corneal ectazia this evaluation suppose to perform donor corneal flap graft.      

The purpose of this study is to investigate the effects of shocks on welfare loss under fractional and full reserve banking. To achieve this goal, we designed a stochastic dynamic general equilibrium model of the new Keynesians, considering the fractional and full reserve banking system (FRB) and the realities of the Iranian economy. We then examined the effects of impulses under two scenarios. After determining the model input values and estimating the parameters using quarterly data from Iran’s economy during the period of 1991-2021 via the Bayesian estimation method, the results of the model variables simulation validate the model’s ability to describe the fluctuations in Iran’s economy. Examining the dynamics of the model shows that the final result of shocks in fractional reserve banking on most of the real and financial sector variables is longer and larger than in full reserve banking. Also, the comparison of the response functions of the selected variables in the two models shows that banking has caused the share of shocks in creating the fluctuations of key variables to change, and even the position of some of them with oil shocks and money changes. Regarding the welfare loss of shocks in two basic and optimal models, the results showed that the lowest welfare loss is related to the optimal model (full reserve). The lowest welfare loss in the basic model (0. 01479200) and the optimal model (0. 00001306) corresponds to the case where the coefficient of the production gap in the loss function is equal to 0. 5. That is, if the inflation priority is applied to the loss function, the numerical value of the welfare loss is significantly smaller than the other investigated cases. This confirms that in both models, the priority of inflation is more effective than the priority of production in the CB loss function in terms of welfare. This means that the Central Bank of Iran should pay more attention to inflation between inflation and production fluctuations because the full reserve of deposits has a greater impact on inflation.

Generally, the various economies can be affected by balance of payments shocks based on their structures. The purpose of the paper is to evaluate the effects of different balance of payments shocks including shocks of oil export, non-oil export, consumption import, intermediate import, and capital import on the welfare losses. It should be mentioned that the macroeconomic environment of a country can be effective in deepening or reducing the impact of balance of payments shocks. For this purpose, based on the New Keynesian approach, a dynamic stochastic general equilibrium model has been developed and simulated for Iran's economy. The results show that the real exchange rate is the most important channel in transmission of balance of payments shocks. Also, the shocks of oil and non-oil exports cause the biggest welfare losses, respectively. Moreover, the results of import shocks mention that although the output loss caused by the shocks of intermediate and capital imports as production inputs is important, but the shock of consumption import through the real exchange rate fluctuations causes the more welfare losses than other type of imports. Hence, to reduce the welfare losses caused by the balance of payments shocks, stabilization of the foreign exchange revenues from oil exports, diversification of the non-oil exports along with the promotion of domestic production and stabilization of the real exchange rate by conducting proper monetary and fiscal policies, are necessary.JEL Classification: C23, E52, E58, G01