Matrix population models, which are as a result of studies by Bernadelli (1941), Leslie (1945,1948), and Lewis (1942), have provided a good basis on which to analyse population dynamics, using the algebraic theory of matrices, with populations divided into age-classes. Of particular importance is how the stable population structure looks like and this is found by a computation of the dominant eigenvalue of the Leslie matrix, whose eigenvector describes the stable age structure. In this paper, an analysis of how changes in the Leslie matrix entries affect population growth is considered. In particular, we investigate how changes in fertility rates and transition probabilities at different stages affect population growth. We compare the population parameters so as to determine which one among them would impact more on the population growth factor.