Subsistence in Rural Areasof Khuzestan Province (1979-2009)

Introduction
In human history, hunger, unemployment, and poverty have been the concern of human society. Poverty has been always with human being as one of the major issues in human societies and cultures. It seemed along with the Renaissance and the industrialization, the problem have been tried to be resolved. But following the industrial revolution and migration from rural to urban and industrial areas poverty and inequality increased and led to an unprecedented social and political chaos and instability. One way to understand the living conditions of households is survey about their consumption behaviour. There are many studies attempted to explain consumer behaviour and consumption expenditure ability to adapt with the price changes throughout the world. These consider different parameters of the economic-social characteristics of individuals or communities. Division of statistical population in geographic categories can give more specific results about the welfare status of residents in specific geographic areas (The Research Institute of Management and Economy). Due to the complexity and multidimensional nature of poverty in the resources and research, different definitions have been presented. But all of them indicate normative concept of poverty and believes that only with predetermined definitions, poor and non-poor can be separated. This Suggests that poverty is always a comparison between a view and a predetermined condition. These differences can also be the first arising from thinking about the philosophy of human existence, his social role, the concept of social justice, belief in the individual authenticity or the popularly authenticity, condition of ecosystem. Second, the extent and diversity of human needs, by considering each of them, lead to a new definition of poverty. Human needs are different in terms of time, location, stage of progress and civilization, technical condition, and cultural levels
 
Methodology
In the present study, linear expenditure system is used to estimate the poverty line. Stone- Gary Utility function can be extracted from a linear expenditure system. The error of structural equation is usually confronted with the problem of serial correlation. There are two solutions to this problem. The first is using of generalized method of Hansen that corrects Covariance matrix for the Auto-correlation and facilitate statistically valid deductions. The second method is using estimator of generalized least squares with instrumental variables, which is known as Multi-stage least squares estimator. These solutions are widely used. Linear expenditure system based on utility function of Stone- Geary cases, using generalized method of moment, is employed to assess the behaviour of rural consumers in Khuzestan Province.
 
Results
The estimates made for the minimum subsistence for a rural household in Khozestan Province indicate that the minimum necessary expenditure for a rural household with an average family size of 6.9 people in 1979 was equal to253634.3 RLs and 1634802 RLs in 1989. This minimum subsistence for a rural household reached 9129691 in 1999 and 44164773 RLs in 2009. In other words, a rural household in khozestan province every month spent 21136 RLs on average as the minimum necessary costs in 1979. With increase in the prices, it reached 136233 per month on average in 1989. After a decade, this minimum monthly necessary expenditure reached 760807.6 RLs in 1999 and 3680398 in 2009. The minimum subsistence package for each rural household suggests that the food was the largest and the transportation and communication the smallest groups. Food, clothes, housing, and recreation as the necessary goods, and transportation, communication and health were considered the luxury. Comparing the minimum necessary expenditures of rural households implies that Kuzestan Province has a higher minimum subsistence compared with that of Semnan Province. The minimum necessary expenditure of rural households inthe province is higher than that of Semnan Province. The minimum subsistence package of each rural household shows that food comprises the bulk and transportation and communication the minority. With calculated numbers and β in the equation system, it is noteworthy that rural households in Khuzestan Province spend more costs on food, drinks, tobacco, and furniture and less on housing, fuel, water, electricity, and clothes among others.
 
 
Conclusion
Food, house, clothes and recreation groups are considered the necessary goods, and furniture, transportation, communication and health the luxury ones among the eight groups of goods in rural households of Khuzestan Province. Rural households Cross Elasticity table indicates that the higher the prices of other goods, the more the reduction in consumption regarding communication and the less in connection with clothes and recreation.