Astronomical housing prices across the country are driving more people to the streets.

Across the U.S., homelessness has risen 0.7% since 2016 and this year, more than 550,000 people slept on the streets each night.

Because wages have not kept pace with the cost of housing, much of the U.S. population now spends more than half of its income on housing costs — meaning those keeping a roof over their heads are barely managing to do so, Fast Company reports.

When the economy improved following the recession, it was a positive for many, but it also proved to drive up housing costs. Despite the upswing, wages did not increase nor have they since the 1970s. In fact, if inflation is taken into account, the median hourly wage has only increased by 0.2% per year since that time, according to Fast Company.

The problem is particularly dire in markets like Seattle and San Francisco, which have welcomed a number of tech companies in recent years. As a result, these areas have witnessed the worst spikes in housing costs. In San Francisco, where there is also an affordable housing shortfall of at least 40,000 units, this has become a serious problem for much of the population.

While solving this affordable housing crisis is far from simple, some cities are actively working to find a solution. In Seattle, the city has proposed placing an extra tax on corporations that would be put toward homeless housing and affordable housing options, such as community land trusts.