The cultural expectations for the proper timing of life events, such as getting married or retiring, are called:

The answer is social clock. It can be named as the social desires that are given by a culture about when the transitional occasions like marriage, having children, or retirement should happen throughout everyday life. The possibility of a 'clock' means the recognizable proof of specific accomplishments or occasions in existence with a specific age or a time of one's lifetime. By 'social', it alludes to the regular conviction existing in a general public about the movement of human life, portrayed in partitioned stages.

Complementary goods. they go together, thats why one price increase and the others demand increases