Question I'm a rising senior economics major, and I'm trying to make a decision about my career. I want to do as much good as possible, but I'm not sure how to estimate how much good I would produce in different careers. I've researched the evidence-based approaches that some philanthropic foundations use (e.g., the "impact planning" of the Bill & Melinda Gates Foundation), but their formulas, etc. don't seem generalizable to calculating an individual's marginal impact. For example, maybe it makes sense to donate a lot to global health but not pursue a career in it because there are already so many working in development. Right now I'm assuming that anything really important will eventually be achieved, so any contribution I make will consist of just coming up with an idea/implementing a project sooner than it would have otherwise. So how about this formula: (N * T / L) * Q Where N is the number of people in the population I'm targeting, T is how much sooner I come up with an idea/implement (e.g., a year sooner than someone else), L is the average lifespan of a person in the population (making T / L the extra fraction of a targeted person's life in which they benefit from the contribution and N * T / L the adjusted number of lives I'm affecting), and Q is the percentage increase in the goodness of the person's life, making N * T / L * Q the number of quality-adjusted lives I'm helping. So if a U.S. education program is implemented a year earlier because of me, there are 50m students, and this increases the quality of a student's life by 1%, is my impact: (50m * 1 / 80) * 1% = 6,250? All this seems confused, but I can't think of a better formula! Please help!!!

Accepted:
June 5, 2011

Comments

There are some technical issues with your formula. You need to decide whether you want to understand L as a constant (80 years), thus assigning equal value to each year of human life, or whether you want to understand L as a variable that varies from person to person, thus assigning greater value to life years of persons whose lives are short. There are plausible arguments on both sides.

You might also rethink your reliance on percentage increase in the goodness of a person's life/time. Do you conceive of goodness as being always a positive number? And do you assume there to be some upper bound such that goodness can vary, say, between zero and one? Assuming all this, your formula is prioritarian: you give greater weight to those who are worse off. Thus, according to your formula, getting someone from 0.01 to o.11 is 50 times more valuable than getting someone else from 0.5 to 0.6 (+1000 percent versus +20 percent). Prioritarians often use a different formula, measuring down from the top or from some sufficiency threshold and then tagging on some exponent greater than 1. If the exponent is 2, then this formula yields a value of 0.99^2-0.89^2=0.188 for the first improvement and a value of 0.5^2-0.4^2=0.11 for the second improvement. Here the first improvement is not even twice as valuable as the first.

Leaving these technicalities aside, it seems plainly false to me to assume that "anything really important will eventually be achieved". There are, to use your own example, billions of ways of organizing education in the United States. Do you really think the best of these will eventually be achieved? In many ways, the last thirty years have been the opposite of progress: there have been more chronically undernourished people in the last two years than ever before in human history, for example, and similarly for environmental degradation, resource depletion, and the rapidity of climate change. So I think there are real opportunities not merely to accelerate progress but also to stave off retrogression or to turn retrogression into progress.

The fact that there are so many possible futures (billions of ways of organizing education in the United States, etc.) also saddles you with a baseline problem. If you devote your life to improving the US education system, how will you know how this system would have evolved without your efforts? I believe that such impacts of persons are next to impossible to ascertain with any precision, even long after the fact. For example, how would the world have evolved if Immanuel Kant had died in his crib? I doubt anyone can provide anything like a solidly grounded answer to this question.

This thought of Kant suggests two further points. First, even if you devote your life to the improvement of the US education system, the effects of your life will reverberate throughout the entire human world (witness the "non-identity problem" as one example of such reverberation -- how you decide to live will likely affect who (in terms of DNA) will be born in the future). Second, the effects of your life will last into the distant future, quite possibly making much more of a difference in the fourth millennium than in our 21st century.

The upshot of these last three paragraphs is that, even if you're well on your way toward a reasonable formula, it will be next to impossible to obtain the empirical data and -- especially -- the predictions that the formula requires. In the end, you'll have to make an intelligent guess about how you can sustainably add the most to the collective effort to make this world better. (Here "sustainably" alludes to yet another uncertainty: concerning your adherence to your original plan. It makes sense to choose a path that you will find interesting and challenging so that you will be happy and productive in its pursuit and will want to stick with it rather than switch out before you can really achieve much.)