In this study, the rate of Time Preference as the most important origin of interest is studied. It is firstly examined from the view point of its determinants and then the affected factors from Time Preference will be considered. Results show that the most important affected variable is saving rate, so that the higher the rate of Time Preference is the lower the optimal saving rate. This can be explained by the fact that the high the Time Preference the more distance one takes in his allocation choice from rational norm. We also claim that Time Preference can not provided enough bases for existent of market rate of interest. This variable have been examined for Iranian economy with Structural Equations, Multiple Indicator Multiple Indicator Cause model (MIMIC) for period of 1351-81. The results also show that increase in Time Preference rate decreases private investment intensively.

The rate of Time Preference plays an important role in discounting instantaneous utility in economic growth models and also in calculating social discount rate in cost-benefit analysis. In empirical researchers, this rate is assumed to be constant. However, the rate of Time Preference might vary over Time. This paper develops a new algorithm to estimate this rate as a varied coefficient for the Iranian economy over the period 1965-2010. In our algorithm, we use a recursive method to estimate the initial values for the rate of Time Preference as a function of consumption. Given the effect of the rate of Time Preference on saving, and knowing their initial values, we use a filtering method to estimate these rates as a function of life expectancy. The average value of Time Preference rate over the period under consideration is 2.38 percent. This rate is found to be higher during the period of economic uncertainties such as Iran-Iraq imposed war. However, the rate is decreasing after the end of war.

Introduction: Consider importance of Time management in educational achievement, job performance and life quality, different research were conducted to indicate the per coming of Time management. The purpose of this study was to investigate the relation of conscientiousness, tenacity and Preference for organization with Time management.Method: Three hundred four mohaghegh ardabili university undergraduate students (1 52 females, 148 males) were selected with cluster random sampling method. All students through descriptive- correlation research method, completed Time management questionnaire (Barling, Kelloway & Cheung), NEO Five-Factor Inventory (Costa & McCrae), Time style scale (Usunier & Valette - Florance), Time management behavior scale (Macan et al).Results: The data from causal modeling (path analysis) indicated that better Time management in direct way was accompanied with higher level of conscientiousness, tenacity (persistence), and Preference for organization (Ps<0.05).Tenacity and Preference for organization also affected by conscientiousness (Ps<0.05). Also conscientiousness via tenacity and Preference for organization effects on Time management indirectly (Ps<0.01).Conclusions: With the change and control of conscientiousness, tenacity and prefer to organize we can improve the Time management and provided success of individuals.

Preference value means livestock Preference to eat some plants relative to other plants or species. Accordingly, by studying the Preference values, the range managers could determine the rangelands grazing capacity to achieve the optimum performance of livestock and to guarantee the stability of rangeland ecosystem. The objective of this study was to determine the Preference value of perennial grasses using two methods of Preference index (species feeding frequency) and sheep grazing Time (feeding Time recording) in a semi-steppe rangeland in the middle Alborz Mountains of Iran during four consecutive years (2010-2013). The collected data were tested for normality and then, analyzed by the software of SAS9.1. The means comparisons were made using the Duncan method. Results showed that sheep preferred five grass species (Bromus tomentellus, Festuca ovina, Dactylis glomerata, Agropyron intermedium, and Agropyron trichophorum) in the rangeland. There were significant differences between species and years for grazing Time method; however, there were no significant differences for Preference index. Also, there were significant differences between months within years for both methods. Results showed that A. trichophorum with the average value of 13.8% grazing Time was ranked as the first species followed by D. glomerata with the average value of 11.1% as the second one (Grazing Time method). There were no significant differences between A. trichophorum, B. tomentellus, D. glomerata and F. ovina regarding the Preference index with the average values of 0.57, 0.75, 0.70 and 0.56, respectively. Overall, the results indicated that grazing Time percent method in semiarid rangelands gives more realistic results as compared to the Preference index method because of the concrete and tangible results.

Time Preference has a peculiar role in determining the level of economic activities. Time Preference is the most important origin of interest rate. In this paper we study the founders and defenders' viewpoints about Time Preference and then we try to criticize them. It seems that discounting future utilities is resulting from irrationality and it is ethically indefensible too. From mathematical aspect, discounting is necessary because it convergences sum of social welfare function to some finite number and so the optimal Time path for consumption is attained. But this isn't true for a growing population. It seems that there aren't any rational reasons for preferring current generation's welfare to future generations'. If we have Time Preference, in intertemporal allocation, it reduces available resources for future consumption and so the level of saving will be decreased. We study a numerical example for affecting Time path of an ore extraction of a nonrenewable resource. Results show that the higher the Time Preference, the higher the rate of extraction will be occurred. Because with a high rate for Time Preference, present value of cash flows will be discounted more strongly and it increases the incentive to mine the more quickly.

Trophic breadth niche, prey Preference and developmental Time of an unidentifiedBalaustium sp. (Acari: Erythraeidae) were studied under laboratory conditions. The prey offered consisted of immature and adult stages of Tetranychus urticaeKoch, Bemisia tabaci (Gennadius), Frankliniella occidentalis (Pergande) and Macrosiphum euphorbiae (Thomas). The breadth of the trophic niche increased as mites developed. All active stages of Balaustium sp. consumed more than one kind of prey. Adults were the most generalist while larvae can be considered oligophagous. Larval instar significantly selected T. urticae eggs, deutonymphs substantially chose whiteflies, and thrips nymphs and adults were non-selective, eating any type of prey they could catch. Details of the development of the different stages are provided.