You’d have to have a pretty cold heart not to be moved by this story: an empathetic doctor and a homeless inventor partner together to launch the homeless man’s invention, changing both their lives in the process.

The story of Mike Williams, who became homeless after a series of financial setbacks, reminds us that as much as we’d like to believe otherwise, none of us are immune from personal disaster. Even for those with great talent or success, like Mr. Williams, hardship or homelessness could be just a short run of bad luck away.

The invention in question is a six-foot by six-foot pod with a chemical toilet, a “secure, safe place for the homeless and people [who] are displaced in society.”

Providing a safe place for people to live is a laudable goal. And no doubt, Mr. Williams has the skill and ingenuity to create something truly useful to many people. But a so-called survival pod is not a solution to homelessness.

Homelessness is not a permanent aspect of our society, nor is it a logical, unavoidable side-effect of capitalism that we must all come to accept. We should not strive to make homelessness easier for people; we should strive to end it. Homelessness exists because the housing available in our communities is too expensive for low-wage workers, seniors and people with disabilities to afford, and because some people have additional personal challenges like mental illness or domestic violence that make maintaining their housing even harder.

Survival pods, like homeless shelters, are at best an interim solution. What is necessary is for the supply of housing affordable to the lowest income Americans to increase. It is not complicated, and it can be done. Our proposal is to fund this increase through a modification of the home mortgage interest deduction that will make home ownership tax benefits available to more middle and lower income home owners, while simultaneously producing savings that can be invested in the production and preservation of housing affordable to extremely low income renters.

When it was signed into law in 2008, the National Housing Trust Fund was a beacon of hope for housing and homelessness advocates. The financial crisis of that year postponed its initial funding. But the country’s financial climate- and its political climate- have changed. Our conversations with Senators and their staffs have convinced us that the mortgage interest deduction as we know it is not long for this world. We have the chance, this year, to influence this rare and welcome debate. Our hope, and our effort, is renewed.

Mr. Williams, like all the rest of us, deserves the dignity of a safe, decent, affordable place to call home. Join with us in support of housing policy that will get us there.