نموذج ريتشارد لمتوسط دخل الفرد : دراسة تحليلية للفترة 1999-2010

Abstract EN

In spite of the significance of nonlinear regression models, studies related to them are very rare compared to those related to linear regression models.

Yet they are widely applied in applied and natural studies.

There so many types of nonlinear or growth model; but this research only tackles the most important and most famous nine of them these are : Negative Exponential Model, Monomolecular Model, Mitcherlich Model ,Gompertz Growth Model, Logistic Model, Chapman Richards Model , Von Bertalnffy Model , Richard's Model and Weibull Model.

The Gauss Newton frequency method has been used in this study, which is characterized by its accurate parameter estimation, while it is difficult to solve other natural equations through the other estimation methods, like ordinary least squares (OLS) or the maximum likely hood method (ML).

This work has applied the Gauss Newton method to the data represented the average per capital income as the unindependent variable and some factors affecting them in Sudan, which are independent variables; such as the GDP, population, investment size and expatriates net transfers during the specific time period 1990- 2010.