The innermost DO loop (i=1 to 200) does not contribute to the number of observations in dataset LIKELY. It populates the array MLE. The number of observations is a product of six integers (hence probably quite large): The number of observations in ONET and the numbers of iterations of the five "outer" DO loops. From your initial post, we know only one of these six factors (51) and that three of them are equal.   So, a useful check (in addition to looking at a couple of observations) would be to compare the number of observations in LIKELY to the product of the number of observations in ONET and the expected numbers of iterations of the five "outer" DO loops (derived from the start, end and step size values). Due to the PROC SORT step, the values of the index variables in the first 50 observations of dataset LIKELY are hard to predict (at least for me) and most likely not representative for the dataset. ... View more