You know how college costs today seem nearly out of reach for all but the most affluent families?

How so many families now are under financial stress and struggling to pay their bills, despite holding down jobs and working hard?

How housing prices in New York City keep climbing faster than wages, forcing more families to move farther out or to the suburbs?

That is income inequality at work.

Bill de Blasio made it the touchstone issue of his mayoral campaign. President Obama focused on it in his State of the Union address. Occupy Wall Street helped us all start talking about it.

The statistics are alarming. Since 1979, the share of total income going to the top-earning U.S. households nearly doubled. In 2012, the top 10 percent of earners took more than half of the country’s total income. An international study in 2013 found that the widest gaps between rich and poor are found in four countries: Chile, Mexico, Turkey and the United States.

The issue really hits home, though, when we consider how growing inequality hurts ordinary people and narrows the future possibilities for our children.

There are ways to close the income gap, and the president is right that government has a big role to play. Solutions include increasing the minimum wage, closing corporate tax loopholes and strengthening labor laws so that workers who want to unionize can do so.

As a union, our fight for fair contracts acts as a counterweight to the rising tide of inequality. So does our support for other labor campaigns, such as the fight by fast-food workers for decent wages.

Inequality affects us all every day. It is, as President Obama said, the defining issue of our time.