The separability of consumer desires is a necessary condition for multi-stage budgeting and collectivization is consistent of commodity where costs are allocated between edible groups using price indices and intergroup allocations are made independent of other groups. In empirical studies of demand, the concept of separation is used to correctly estimate demand function and limit the number of parameters. For this purpose, data related to price index and cost of selected commodities (citrus fruits, cucurbits, and vegetables) derived from the Central Bank over 2016 in urban households of Iran were used. The results of the separability tests support the hypothesis that consumers first allocate their income to selected commodities in three groups (citrus fruits, cucurbits, and vegetables) and then approves the income allocation action between the types of its subgroups that are grouped. Also, the results of the system estimation showed that all groups had a negative intrinsic price elasticity. In the meantime, the price elasticity of the groups of citrus fruits (orange, tangerines, and lemon), cucurbits fruits (potato, tomato, and onion) and vegetables (the leafy ones) are equal to -0.83, -0.48 and -0.91, respectively. Given the income elasticity calculated for the three commodity groups, the second commodity group (potato, tomato, and onion) is more essential than the other commodity groups, which should be considered in government policies as to agricultural production and pricing. Manuscript profile

Economic appraisal of historical sites is the key to planning rural development for their management, preservation, and protection. The purpose of this study was to estimate the preservation use value accrued to visitors to Rudkhan Castle in the northwest of Gilan Province, Iran. The visitors' willingness to pay (WTP) was measured by using the contingent valuation method (CVM) and the one-and-one-half-bound (OOHB) model’s dichotomous choice (DC) questionnaire. Throughout the research, we stressed the fact that indifference, uncertain, and protest behavior can and do occur simultaneously in contingent valuation (CV) studies. The results showed that 75% of the people in the protection program of Ghaleh RudKhan Castle are willing to pay. The rest are not willing to contribute and are divided into three groups: unwilling to pay (4%), protests (20%), and uncertain (1%). Using the OOHB bid function, an expected WTP recreational value of US$ 0.566 per visit per household was estimated in 2019, and the annual welfare surplus of visitors was estimated at US$ 96250000. The average WTP in the ethical and consequentialist groups was estimated at US$ 0.643 and 0.67325, respectively. Also, the group unwilling to pay or true zeros was composed of seven respondents who explained their reasons as personal budget restrictions (86%) and the unnecessity of the program (14%). The protests group was also composed of 33 respondents and argued that it is only the task of the government (38%), only rural residents should pay (3%), only nonresidents should pay (56%), and not enough information is given on the proposal (3%). Manuscript profile