The aim of this study was to evaluate the spatial effect of income inequality, relative poverty, real per capita income growth, unemployment, real exchange rate and real interest rate on real purchasing power of durable goods using the generalized SAR-GMM-DPD spatial self-regression torque model with two-stage coefficients. Arellano-Bover / Bundell-Bond is a random dynamic band between provinces of Iran in the period 2006-2017. The results show that according to Dosenbury's theory of consumption theory, durable goods have a broken demand function; Thus, the first interval of the dependent variable with a coefficient of 0.009 has a positive effect on the purchasing power of durable goods. The first spatial interval of SAR is also negative and significant -0.007 which indicates the negative spatial dependence between the provinces of Iran, ie the effects of independent variables on the dependent variable have indirect spatial and geographical effects. Income inequality with a coefficient of -0.43 has a negative effect on the purchasing power of durable goods of households. The relative poverty line with a coefficient of -0.06 has a negative effect on purchasing power, and as the relative poverty line moves to the upper deciles of income, the purchasing power of durable goods decreases.

Cash that its Khums has been paid and is stored in banks in order for business or savings is sometimes faced with an increase in the purchasing power. Some acceptable scientific and jurisprudential comments have been made on the devaluation but no research has been conducted on revaluation. The question is whether Khums is belonged to the increase in the purchasing power. In other words, is the revaluation considered as the quintessence of interest, *, and business so that Khums is belonged to? Given the aforementioned titles being customary in order for Khums belonging, if custom regards the increase as the quintessence of interest, *, and business, Khums is belonged to and if the custom judgment is on non-compliance of the purchasing power increase, Khums is not belonged to that increase. In case of lack of recognition with Ijtihad reasons on the increase in the purchasing power of money, principles of acquittal and presumption explain that Khums is not belonged to the increase in the purchasing power of money. The research assumption is proved in a descriptive-analytical way, by collecting library data, and by utilizing rational methods. The result of the present study is that, considering the fact that the purchasing power of money is the valuation of its nature, Khums is belonged to the increase in the purchasing power because the titles interest, and business are true.

The Relationship between productivity of economic sectors, effective real exchange rate, and purchasing power is a burning economic issue. Based on the “Balassa – Samuelson” theory, higher economic productivity for tradeable goods leads to an increase in effective real exchange rate which is indicative of higher value of domestic money and higher purchasing power of money. The purpose of this study is to examine the Relationship between the difference of productivity and inflation in commercial partners of Iran and its effect on effective real exchange rate by incorporating the purchasing power parity for 1980-2011. For analysing this relationship we use “Pedroni Cointegration” method and of FMOLS. The results show the effect of “Balassa – Samuelson” in these countries in a way that an increase in productivity of tradable goods leads to an increase in effective exchange rate. Besides, the results show a negative effect of a decreased real exchange rate on purchasing power of Iran for future years.

The change in the composition of the household consumption basket is one of the effects of decreased purchasing power. Tourism sector is one of the sectors that will be most affected by this change. But the different nature of the “tourism product” from other economic goods, as well as regional differences in the type of tourist spending, overshadows how household spending in the tourism sector is affected. This study aimed to investigate the change in household behavior in tourism expenditures that are affected by various factors such as changes in household purchasing power, and for this purpose has used the spatial data panel model during the period 2011-2019 for 31 provinces of Iran. The results has shown that household purchasing power has a negative effect on the share of household tourism expenditures. Results also examining the effects of some of the most important variables of household budget, it can be analyzed that the change in household purchasing power does not directly reduce the number of trips or the tourists’ length of stay, but it affects the type of travel and the change in the household travel pattern. It also leads to changes in choice of destinations.

Equity in purchasing power remains an important issue for scholars in the international economy. The validity of this theory is important not only for empirical studies but also for policy makers. The PPP theory holds that due to arbitrage in the international commodity market, the real exchange rate is expected to return to its equilibrium level in the long run. Finally, the researchers concluded that one of the major macroeconomic issues that has been linked to many political debates is the exchange rate, which is a non-linear real exchange rate behavior. Given the importance of the subject in this study, we decided to investigate the asymmetric measurement of purchasing power parity test using nonlinear self-regression model with intermittent distribution. In this context, Iran's purchasing power parity with Japan, Norway, Saudi Arabia, Britain and the United States was examined during the period from 1960 to 1986. The results show that in the long run, price shocks have an asymmetric effect on purchasing power parity in Japan, Saudi Arabia, and the United States, while they are symmetric in Norway and the United Kingdom. Moreover, in the short run, price shocks in Japan and Saudi Arabia will have an asymmetric effect on purchasing power parity, while the effect of price shocks in Norway, England and the US on purchasing power parity will be rejected in the short run.

The purpose of this study is to empirically investigate the theory of Purchasing Power Parity for Iran during 1339-1391. In order to do this، Zivot-Andrews and Lee Strazicich unit root tests، which take the possibility of structural breaks into consideration، have been used. According to the results، the null hypothesis of Zivot-Andrews and Lee Strazicich unit root tests for real exchange rate، i. e. there exists unit root، could not be rejected، and thus، it cannot be concluded that real exchange rate is stationary. The non-stationarity of real exchange rate in turn means that the hypothesis of existence of Purchasing Power Parity in Iran is rejected. To ensure that these findings are valid، Saikkonen Lutkepohl and Dynamic OLS co-integration tests were also applied. These tests confirm the results of pervious unit root test as well، and show that the Purchasing Power Parity theory is not workable for Iran over the period in question.

One of the main factors influencing consumer behavior is economic conditions. This research has been done on the subject of "A Survey in effects of reducing purchasing power on buying and consumption of detergent and cleaning products among consumers in Tehran". The purpose of this research is analyzing the effects of decreased purchasing power on the consumer in detergent products. In this research different factors affecting the consumer behavior, the way these factors enter the consumer black box and are processed under the influence of motivations, attitudes, perceptions, and learning have been discussed. This research is categorized as a descriptive – survey study. The research is categorized as an application survey on a purpose basis. Questionnaires were used for data collecting. 440 questionnaires were distributed and 384 of them were used for analysis. Based on the results of the survey, after processing collected data, all five hypotheses were confirmed. The results show that decreasing purchasing power has had an effect on all stages of the consumer behavior process.

This article examines the role of the sale date in determining buyer compensation and regularization in Supreme Court unanimous decision No. 811. It discusses the challenges faced by courts in calculating compensation for the decrease in purchasing power of the buyer's cash price and the issuance of conflicting decisions. The article analyzes the purpose and desired outcome of the unanimous decision, provides a systematic interpretation of its provisions, and concludes that the sale date price is primarily a criterion for determining inflation rather than a direct measure of total compensation. After the conclusion of a contract, the buyer may discover that the object of sale is defective. In such cases, the seller is obligated to return the price and provide compensation to the buyer. Due to the lack of clear criteria in the laws regarding the calculation of compensation for the decrease in purchasing power and the absence of consistent judicial procedures,the Supreme Court issued two unanimous decisions on this matter. In 2014, unanimous decision No. 733 established the principle of considering the decrease in purchasing power as a compensable loss. However, the criteria for calculating this decrease remained disputed. Some courts used the general inflation index, while others considered the inflation rate for specific goods. These differences led to the issuance of unanimous decision No. 811 in 2021. Despite this decision, confusion persists regarding the role of the "price on the day of sale" in determining buyer compensation. Some courts consider this price as the total compensation, regardless of the price actually paid by the buyer. Others use it as a criterion for calculating inflation. This article argues that the price on the day of sale is primarily a criterion for determining inflation and cannot be directly equated with total compensation. The purpose of the unanimous decision is to compensate the buyer for the devaluation of their money due to inflation and to restore their purchasing power. To calculate compensation, two criteria can be used: General inflation index:This is a central bank index that measures inflation based on a basket of goods. Inflation rate for specific goods:This measures the increase in price of similar goods to the object of sale. The choice of criterion depends on the circumstances of the case and the buyer's intended purchase. The goal is to restore the buyer's situation to the day before the contract was concluded, so that they can have a similar purchasing power. Unanimous decision No. 811 is significant in that it establishes the objective inflation criterion as the basis for compensation. This provides greater protection for buyers in cases of defective sales. In conclusion, the price on the day of sale is an important factor in determining buyer compensation, but it should not be used as a direct measure of total compensation. The goal is to compensate the buyer for the loss of purchasing power due to inflation, taking into account the circumstances of the case and the price paid.

Main objective of this paper is to evaluate supportive policies of beef producers during the first, second, third and fourth terms of Economic, Social, and Cultural Development Plans (1989 - 2008).To evaluate the policies, the Producers Support Estimate(PSE) index and other indicators (PSE %, NPC & NAC) were used. Furthermore, percentages of PSE were calculated in different scenarios of exchange rate (such as black market exchange rate, purchase power parity (PPP) exchange rate, 5 percent increase in purchase power parity (PPP) exchange rate and 5 percent decrease in purchase power parity (PPP) exchange rate). The results presented that market price support (MPS) of beef producers had increasing trend during development plans, especially in the first and the second plans. The government’s budgetary payments (BP), on the other hand, presented decreasing trend from 4 billion Rls (local current) in the first development plan to 2 billion Rls in the forth development plan. Furthermore, total support estimate (PSE) of beef producers increased during the fourth terms of development plans. It is concluded that share of MPS in total producers support estimate (PSE) is more than BP. The study results presented that, in all terms of the development plan (except for the first plan), percentages of PSE calculated by purchase power parity (PPP) exchange rate were higher than amounts calculated by black market exchange rate. PSE% was found sensitive to changes in the exchange rate.

Purchasing power of earned income and family consumption expenses, are among the main drivers of farmers’ welfare. One can predict any improvement in well-being of agricultural producers based on their purchasing power enhancement which, in turn, is related to domestic terms of trade index (DTOT). Present study aims at analyzing the relationship between monetary policies and farmer's welfare using vector autoregressive model for the period from 1981 to 2012.The Johansen test results confirm that DTOT index is directly and significantly affected by sector growth, inflation, interest and real exchange rates in the long term. Furthermore, the estimated error correction model recognizes a dynamic two-period lagged relationship among aforementioned variables in the short term. Reconsideration of agricultural support policies in order to neutralize the possible adverse impacts of macroeconomic variables’ changes, is recommended.