Logical puzzle

A LOGICAL PUZZLE FOR THE MINNOWS, CARPS, SALMON, TROUTS etc.   For a statistical study an agent analyzed the family structure of a population. The result was the following:   

1) The parents were more numerous than children. 

2) Every boy had a sister. 

3) There were more boys than girls. 

4) Every parent had a child.   

What do you think happened to the agent? 

(see answear below)       

The agent joined the list of the unemployed for being incompetent, becaused he had arrived at the conclusion there were more parents than children.