It is potent:
If people married each other more randomly, poverty levels would be considerably lower than they are now. If we abandoned all current family arrangements and randomly grouped all Bolivians into new families of 5 persons, poverty levels would fall by about 15 percentage points (from the current level of 55% of all households to about 40% of all households). The Gini coefficient measuring inequality would also fall from about 0.70 to 0.55.
But Bolivians do not mix much in marriage. The correlation between partners’ education levels is extremely high at about 0.77, with no signs of falling. For comparison, the corresponding number for Germany is 0.52 and for Britain it is 0.41.
But not all Bolivians are equally restricted in their marriage choices. In the department of Santa Cruz the correlation is only 0.69 while in Potosi it is 0.82, with a corresponding difference in poverty rates.
That is from Lykke E. Andersen, Development from Within, an interesting and well-written collection of essays on Bolivian development, and sometimes on development policy more generally. The cited piece was written in 2008.
Here is a good sentence from that book:
Just one little road block can disrupt an entire vacation.