MBD is calculated by taking the average of the differences between predicted values and observed values. Mathematically, it is expressed as:
MBD = (1/n) * Σ (P_i - O_i)
where n is the number of observations, P_i is the predicted value, and O_i is the observed value. It is important to note that MBD can be both positive and negative, indicating overestimation and underestimation, respectively.
