In order to know which groups need which services and facilities. In order to plan for the nation of the future. In order to gauge the trends and tendencies that mark the unfolding of national history.
In his own way, Moses had a similar purpose when, in obedience to the command of the Almighty, he carried out the census of the people of Israel.
Yet on occasions when it was human and not Divine motivation that led to the counting of people, our tradition frowned on the exercise. Counting people was a transgression in such circumstances.
The question is why.
What does a census ask? How many people we have. Surely it is a fair question!
Yet what does it tell us? In one sense, nothing at all. It reduces human beings to a lowest common denominator. They are numbers, indistinguishable, without personality, uniqueness, emotions, ideas, aspirations, failings and hopes.
More important than counting people is to be able to count on people, allowing each one to bring their own contribution to the well-being of all.