Socioeconomic mobility in the United States refers to the upward or downward movement of Americans from one social class or economic level to another, through job changes, inheritance, marriage, connections, tax changes, innovation, illegal activities, hard work, lobbying, luck, health changes or other factors. This vertical mobility can be the change in socioeconomic status between parents and children ("inter-generational"); or over the course of a lifetime ("intra-generational").