"The likelihood of leaving low pay decreases
dramatically as tenure in a low-paying job increases. Low-
wage employment could itself decrease future wage growth
if it causes workers to receive less training or skill
development, conveys a negative signal to future employers,
or provides access only or chiefly to weaker labor market
networks. Significant numbers of stagnant low-wage
earners could also be visible because of “sorting,” as those
individuals with lower employment opportunities remain low-
wage workers. The latter finding indicates that, not only is
earnings mobility a reality for a substantial number of initially low earners, but also there is continued poverty within a large subpopulation of workers."
In other words, it's not quite as simple as "work will always win".
http://www.bls.gov/opub/mlr/2006/07/art4full.pdf
"The likelihood of leaving low pay decreases dramatically as tenure in a low-paying job increases. Low- wage employment could itself decrease future wage growth if it causes workers to receive less training or skill development, conveys a negative signal to future employers, or provides access only or chiefly to weaker labor market networks. Significant numbers of stagnant low-wage earners could also be visible because of “sorting,” as those individuals with lower employment opportunities remain low- wage workers. The latter finding indicates that, not only is earnings mobility a reality for a substantial number of initially low earners, but also there is continued poverty within a large subpopulation of workers."
In other words, it's not quite as simple as "work will always win".