Why the allusion to Malthus?

Malthus was an 18th century economist. He predicted that rising populations would eventually lead to disease and famine among the poor. As a result, he firmly believed that the size of families among the lower classes should be regulated by the government. By using the allusion to Malthus, Sinclair is pointing out that while many people agree with Malthus in theory, they also feel the necessity to aid the poor.