This work studies the variance of the return over assets (ROA) of 1,664 Brazilian organizations between 1996 and 2003. This variance is divided into in factors associated with differences between business units, imdustries and economic conditions. The model is also calculated dividing the overall period into four year intervals so as to follow the evolution of the factors over the years. Results show that the main source of the variation in the performance can be attributed to differences among companies. The weight of this element increases over time. Surprisingly, considering the many and frequent crises suffered in the last couple of years, the role of the economic climate is slight and similar to that found by other authors for the American market.

This work studies the variance of the return over assets (ROA) of 1,664 Brazilian organizations between 1996 and 2003. This variance is divided into in factors associated with differences between business units, imdustries and economic conditions. The model is also calculated dividing the overall period into four year intervals so as to follow the evolution of the factors over the years. Results show that the main source of the variation in the performance can be attributed to differences among companies. The weight of this element increases over time. Surprisingly, considering the many and frequent crises suffered in the last couple of years, the role of the economic climate is slight and similar to that found by other authors for the American market.