The tendency of humans to move from one city to another, one country to another, or one continent to another, has rapidly accelerated over the past decades, due mainly to employment changes or demands. While moving is said to be the third most stressful event in a woman's life (childbirth and the death of a loved one being the other two), the event can also be very traumatic for the children involved, and can be a causative factor in marital difficulties. (As most "executive" moves are initiated by a husband's career, it is usually the man who is least negatively affected by a move, as he retains his career identity and is very immersed in his work, leaving his wife to attend to the problems of schools, social activities, and acclimatization to different systems and ways.) Moving is also very costly, and if there is little or insufficient aid from the employer, the high price can alter individual and family lifestyles.