We used Excel to do some basic data analysis tasks to see whether it is a reasonable alternative to using a statistical package for the same tasks. We concluded that Excel is a poor choice for statistical analysis beyond textbook examples, the simplest descriptive statistics, or for more than a very few columns. The problems we encountered that led to this conclusion are in four general areas:
Missing values are handled inconsistently, and sometimes incorrectly.
Data organization differs according to analysis, forcing you to reorganize your data in many ways if you want to do many different analyses.
Many analyses can only be done on one column at a time, making it inconvenient to do the same analysis on many columns.