Nowadays, the effect and importance of housing and its role in Iran’s economy cannot be underestimated. Housing as a fundamental and basic need for Iranian households is not just a shelter, but is considered as a crucial asset. It has a superior financial value as well. Expansion in urbanization, especially in Tehran, regarding its financial and political importance has contributed to this situation. In this paper, using time interval data between the years 1981 to 2005, the casual relation between variables which affect housing in urban districts through analyzing and monitoring Granger-Hissao, SIMES causality test, have been utilized and its impacts are examined in self-regression model. The results indicate that there was a causality relation between price of house, bank loans, number of households and their incomes. Nevertheless, house price had the most impact on instabilities of housing during this period.

Although prices of all commodities play a role inconsumers’ decision- making process, the large number of individual commodities and prices creates problems in analyzing consumers’ choice. As a result, to the study consumer behavior, data aggregation is used quite often. To this end, different theories are proposed that justify consistent aggregation of commodities. The Generalized Composite Commodity Theorem (GCCT) and the testing procedure proposed by Lewbel is the original one that considers a necessary condition for consistent aggregation. Davis proposed aggregation testing approaches by resorting to the Bonferroni, SIMES, Holm and Hochburg statistical methods for testing Generalized Composite Commodity Theorem in which the necessary and sufficient conditions are considered. This study is aiming to examine the possibility of aggregating meats, meat products, dairy products and eggs in a group named "Animal Proteins” and aggregating all grains in a "Vegetable Proteins" group, and to compare the aggregation results using Lewbel’s procedure and the approaches proposed by Davis using data over 1990-2012 period. Results show that based on the Lewbel’s method, all animal products except dough, curd and egg can consistently be aggregated in the Animal Protein group, and all grains including split peas, beans and lentils can be aggregated in the Vegetable Protein group. While based on Davis methods, all animal commodities without any exception can be placed in Animal Protein group and all grains are consistently aggregated in the Vegetable Protein group. These results indicate that the latter approach lets a wider range of commodities to be aggregated in a group. This implies that selecting an inappropriate aggregation method can lead to a bias in evaluating consumer behavior.

The main purpose of this study was to investigate the possibility of aggregation different types of pulses as well as sugar, using the single and multiple hypotheses test. The former hypothesis tests include Composite Commodity Theorem (Leontief and Hicks) and Generalized Composite Commodity Theorem (GCCT) and the latter hypothesis tests include the Bonferroni, SIMES, Holm, and Hochberg procedures and the results of mentioned methods were compared. Data of the period 2006-2018 for this study were obtained from the Statistics Center of Iran. . The results of multiple tests of Bonferroni, SIMES and Hochberg for different types of pulses showed that with the exception of “, mixed pea and bean”, , other products can be aggregated into the group of Pulses. Also, based on the results of Bonferroni, SIMES, Holm and Hochberg, different types of sugar can be aggregated into the group of Sugar. The results of the individual hypothesis test are not the same for different types of pulses and different types of sugar. In other words, according to Leontief method, the hypothesis of aggregate the different types of beans together was not confirmed, while according to Hicks method, this hypothesis was confirmed. Similarly, according to the Leontief method, the hypothesis of aggregate the different types of sugar together was rejected, while according to the Hicks method, this hypothesis was confirmed. The result of the GCCT showed that all types of pulses (except “, other beans”, ) can be aggregated into the Pulses group. The types of sugar can also be aggregated into the Sugar group according to the generalized composite method. Based on the results, when the number of observations is low, the use of single tests and specifically the GCCT will not show the exactly same results, which confirms Davis (2003) finding that the GCCT does not guarantee proper aggregation of goods. In these cases, multiple tests would be recommended.

Ten varieties of Iranian soybeans are cultivated in different areas of the country; Persia or Sahar (SR), Hill (HL), Williams (WZ), Gorgan 3 (GN), Clarke (KL), Hawkey (HK), Zaan (ZN), Harcor (HR), Dare (DR) and SIMES (SS), grown in tropical regions. Samples of these 10 varieties were obtained from the Institute of Plant and Seed Research. After sample preparation, their oils were extracted and analyzed for iodine content, saponification, refractive index, specific gravity, peroxide, free fatty acids, color, fatty acids composition, Fe and Cu. Statistical results showed that there were significant differences (P<0.05) between them. Fatty acid profiles showed that the ZN and GN varieties had the lowest and highest linoleic and linolenic fatty acids, respectively. The ZN variety had the highest oleic acid content. It was concluded that the ZN variety is best in chemical composition for oil production, with HR and WZ ranked second and third.

Vegetable oils contain a little amount of phospholipids or phosphatides and in soybean oil compared with other oils usually more phosphatides exists. In the oil refining process, phosphatides exert adverse effects on the quantity and quality of the oil and their presence in the oil distributed in supermarkets could also create undesirable effects during consumption. If, however, phosphatides are extracted properly from the oil, they could have valuable applications such as emulsification in many food systems. Five varieties of soybean cultivated in Iran (Sahar, Williams, Gorgan, SIMES and Hill) were selected for this investigation. Hexane could be used to extract oil and phosphatides but the output of the extracted phosphatides is low. This is due to the polar nature of phosphatides which does not allow these compounds to be completely dissolved in a non-polar solvent like hexane. In fact, the proper solvent for this purpose is a mixture of chloroform and methanol, but such a solvent is expensive and its recovery is costly as well. Thus, a kind of hexane, containing some polar compounds and manufactured in Iran was used for the extraction of oil. With these solvent and relatively severe conditions for the extraction, the amount of the extracted phosphatides increased to 1.72%. Considering that the phosphatides, constituents could affect the process of their separation from the oil and also their functional characteristics, the amounts of individual phophatides form each varieties were determined. The results indicated statistical significant difference among different varieties (P< 0.05). Although, for fatty acid composition, relatively considerable difference was observed among oils from different varieties, this difference was less on the fatty acid composition of their phosphatides.