Montesquieu
 

XVI.3 That plurality of wives depends greatly on their maintenance

Although in coun­tries where poly­gamy is once esta­bli­shed, the num­ber of wives is lar­gely depen­dent on the hus­band’s wealth, never­the­less one can­not say that it is because of wealth that poly­gamy beco­mes esta­bli­shed in a state : poverty can have the same effect, as I shall affirm when I dis­cuss sava­ges.

Polygamy is less a luxury than the occa­sion of great luxury among power­ful nations. In warm cli­ma­tes one has fewer needs1 ; thus it costs less to main­tain a wife and chil­dren. Therefore a man can have more wives.

In Ceylan a man lives for ten sous per month ; they eat nothing but rice and fish (Recueil des voyages qui ont servi à l’établissement de la Compagnie des Indes, vol. II, Part I).