This article was written by by Arjun Khanna and originally published on Dan Ariely's Blog.

As the American population ages, the debate about the ethics of physician-assisted suicide for terminal patients becomes more important.

Proponents of legalizing of physician-assisted suicide argue the practice is ethically justifiable because it can alleviate prolonged physical and emotional suffering associated with debilitating terminal illness. Opponents claim that legally sanctioned lethal prescriptions might destroy any remaining desire to continue living – a sign of society having "given up" on the patient.

Ultimately, these arguments rest on differing opinions regarding the effect of this policy on the patient's wellbeing. The challenge, then, is to determine how legalization of physician-assisted suicide would affect the wellbeing of terminally ill patients and their medical decision-making. Outside of philosophical arguments, examination of an interesting finding regarding physician-assisted suicide – know as "The Oregon Paradox" – can add an interesting dimension to the debate. The paradox is the finding that when terminal patients in Oregon receive lethal medication (under Oregon's Death with Dignity Act), they often feel a sense of greater wellbeing and a desire to live longer. In 2010, of 96 patients requested lethal medication, only 61 actually took it. Even more interesting are the many anecdotal accounts of terminal patients, upon receiving lethal medication, that feel a surge of wellbeing and a desire to persevere through their illness.

Why is this this the case? Looking at this question from an expected-utility perspective suggests that given the option to terminate their own life, terminal patients will decide how long they want to live by comparing the value they expect to gain from the rest of their lives to the expected intensity of their suffering. At the point where future utility is expected to be negative—that is, when the patient's condition becomes so intolerable that living any longer is not worth the cost—the patient would choose to end life if the option were available. The critical point from this perspective is that patients choose the amount of time they are willing to continue living with their illness, which will depend how quickly they deteriorate. If the rate of deterioration is slower than expected, then patients should delay terminating their lives; if the rate of deterioration is faster than expected, patients should desire to end their lives quicker.

But now let us say that patients have been prescribed lethal medication and have the option of ending their lives at any point of their choosing. As before, patients don't want to choose a time too soon or too distant, but with the power to control the end of their lives they no longer have a reason to err on the side of haste! The patients can now wake up every day with the comfort of knowing that they do not have to suffer through pain or stress they might find intolerable.

Being given the option to determine the time of our own death can transform patients from powerless victims of their illness to willing survivors of it. Together, the importance of feeling in control and the ability to reduce (but not eliminate) uncertainty about rate of deterioration adds an interesting new dimension to the underlying ethical debate and seems to provide credence to the benefits of legalized physician-assisted suicide.

It is clear is that we need a greater understanding of the decision-making of patients at the end of their lives, and that with this improved understanding we can construct policy to better protect their wellbeing (for an interesting recent movie on this topic see "How to Die in Oregon").