The teaching quality of Portuguese learning institutions depends on the population that is receiving the training, their family background support, the teaching staff quality and motivation, the sociocultural environment and the economical development of that population. In some ghettos, especially in Greater Lisbon's suburbs where many immigrants, immigrant descendants from PALOP countries, among some other ethnic minorities, are concentrated, and also areas with higher unemployment rates and other severe social problems, exist schools with generalized high dropout and juvenile delinquency rates. In Greater Porto, there are no African or other significant immigrant ghettos like in Lisbon, but there is a high dropout and juvenile delinquency rates among nationals from former rural areas, of humble origins or from ethnic minorities from specific districts or quarters.