The Golden Gate Suicide Barrier Makes Economic as Well as Moral Sense

Because September is Suicide Prevention Month, I have written a piece for Washington Post’s Wonkblog describing the evidence supporting the likely benefits of the $76 million suicide prevention nets that will be installed on the Golden Gate Bridge. This was a compassionate policy decision by the Bridge District Board, who were responding to the agony of many grieving families. At the same time, it was economically defensible by any reasonable standard.

Willingness to pay analysis of lifesaving policies strikes many people, including me, as a bit cold around the heart. But it is also informative for weighing public policy choices because we will never have enough money to pay for every conceivable life-saving option. Was the suicide barrier a good investment from that viewpoint?

Austin Frakt has helpfully flagged a a new review in Health Economics of willingness to pay studies supports $98,879 as a reasonable estimate of how much people will pay for an added year of life. Keeping to round numbers for simplicity, let’s call that 100k and also make the reasonable (indeed conservative) round number assumption that, because suicide is most common among the late middle aged population, the average person who takes their own life would otherwise live another 20 years. That gives a back of the envelope assessment that it’s reasonable to pay at least $2 million to avert the typical suicide.

Based on research in this area, the nets on the Golden Gate Bridge can be expected to prevent (i.e., not just shift to another location) a suicide a month, which works out to a $24 million dollar return per year. Note that this estimate is even more conservative than it seems because the Bridge attracts more young adult suicides than do other means of suicide (i.e., they will live more than 20 more years), and, because there is clearly added value in averting the emotional suffering by the loved ones of people who jump from the Bridge.

Again rounding to keep the math simple, this means the investment in the suicide barrier pays for itself in a little over three years and then yields a massive return on investment forever after (If one assumed a million dollars of maintenance a year on the suicide prevention nets after they were installed, their annual economic return would be 2400%). That’s a spectacular return on investment relative to most investments we make in the mental health field.

Another way to appreciate the value of installing the nets, highlighted by Liza Gross, is to compare them to other decisions made regarding the bridge. From that vantage point, the virtue of the decision to install nets is even more obvious:

[The Bridge district] approved toll funds for a $26.5 million median to separate opposing lanes of traffic to prevent head-on collisions. Since 1970, 16 people have died when cars veered into oncoming traffic. Over the same period, more than 70 times as many — at least 1,129 people — have leapt to their deaths.

Author: Keith Humphreys

Keith Humphreys is the Esther Ting Memorial Professor of Psychiatry at Stanford University and an Honorary Professor of Psychiatry at Kings College London. His research, teaching and writing have focused on addictive disorders, self-help organizations (e.g., breast cancer support groups, Alcoholics Anonymous), evaluation research methods, and public policy related to health care, mental illness, veterans, drugs, crime and correctional systems. Professor Humphreys' over 300 scholarly articles, monographs and books have been cited over thirteen thousand times by scientific colleagues. He is a regular contributor to Washington Post and has also written for the New York Times, Wall Street Journal, Washington Monthly, San Francisco Chronicle, The Guardian (UK), The Telegraph (UK), Times Higher Education (UK), Crossbow (UK) and other media outlets.