If it’s harder for people on lower incomes to afford their rent, then more people will end up sleeping rough.
The chart below shows the number of people that were seen sleeping rough in London and compares it with the precentage of their income the typical lower income household spent on private rent.
If the blue bars are higher that means more people were seen sleeping rough that year. If the organse line is higher it means that the typical lower income household had to spend more of their income on rent.

In 2014 there were 6,508 people seen sleeping rough in London and the typical lower income household spent 48% of their income on rent.
In 2016 there were 8,096 people seen sleeping rough in London and the typical lower income household spend 63% of their income on rent.
Poorer people were spending more of their money on rent and more people were sleeping on the streets.
The ‘affordability’ of rents is not the only reason for people sleeping on the streets but it is a very important reason.