To start, let's consider a few problems where protesting could likely make a difference. It seems to me protests rely on having a problem that is fairly concrete and direct, with an identifiable institution at fault. Poverty in developing countries strikes me as lacking in a clear target for a protest, and existential risk strikes me as too abstract and, again, lacking in a clear target.
These are problems that severely affect large numbers of people and are at least somewhat tractable:
-Global institutional reform relevant to poverty
-Immigration and open borders
Now let's look at the costs and benefits of participating in a protest. Carl Shulman writes, "But to be convincing you have to actually show your work that the returns on protesting really are competitive with the opportunity cost of time (e.g. earning and donating some money, studying to advance your career and ability to get things done, doing malaria research, resting up after all of the above)."
Though time is approximately fungible, it seems likely that people sort their time, like money, into budget categories. Given that, we must ask which category protesting is likely to come out of. It seems unlikely it would come out of one's job and more likely to come out of either resting up or self-improvement.
A basic economic approach would value leisure time at the amount one could earn in that time, but going to a protest doesn't obliterate leisure time - it simply replaces the alternative activity with going to a protest. This will be costlier for some people than for others. If marching is a chore, this cost could approach or even surpass the
forgone earnings, but if marching is energizing, or even just benign, the cost could be fairly low. The cost will also, of course, depend on how important your being well-rested is - getting less sleep to march in a protest would be quite costly for a life-saving surgeon.
To get more specific, again quoting Carl Shulman, "If the tens of millions of person-hours spent on the protests were spent at minimum wage jobs and the proceeds donated, then tens of thousands of African lives would have been saved; if one can earn higher wages or contribute in other scarce ways, the opportunity cost will be larger still."
I assume he is going with GiveWell's estimate that $3,340 given to the Against Malaria Foundation can, on expectation, save one life. 300,000 people at, say, the People's Climate March, had they spent five hours at a minimum wage job instead of marching would have earned enough to save about 3,000 lives. As stated above, I don't think that working is the relevant alternative - protesting would most likely detract from mentally allotted leisure time. Still, even if leisure time is worth 1/10th the amount of time that work time is (and the people marching work minimum wage jobs on average), that march had an opportunity cost of 300 lives that could have been saved, a pretty hefty opportunity cost.
How unfavorable is this comparison? Well let's turn to the benefits.
The benefits of any one action are far more diffuse and less measurable than the sort of interventions effectiveness-minded people like to favor. Clearly, the benefits will vary greatly by protest. Each year there are many, many protests with little effect. As someone who grew up outside of Washington, D.C., I can report that every time I visited the White House, I saw a protest outside for a cause that would likely be forgotten.
Yet every so often there is a protest with a profound effect. I cited the People's Climate March in my original post, and that protest, which appeared on the front page of the New York Times, seems to have catalyzed one of the liveliest student protest movements in years, which has kept climate change in headlines across the country and perhaps led to Senate Democrats' scuttling of a bill to approve the Keystone XL pipeline.
Meanwhile, the Black Lives Matter marches have made racism in the criminal justice system one of the principal political issues of 2015, and while police in the U.S. kill 1,000 people each year, the U.S. prison population numbers above 2,000,000, which is significant considering the potential tractability of the problem and the misery of being imprisoned, is a worthwhile problem.
But beyond this anecdotal evidence, there is a fairly strong scholarly consensus that protests work, spanning political science, history, and economics. Specifically, political scientists' estimates of the effectiveness of nonviolent protest movements range from 37% to 75% of such movements achieving their goals.
Of course, that protest movements work does not tell us how well they work, which is what we need to compare participation in them to the alternative. A highly rigorous study of the Tea Party movement estimated that an additional protester at a Tea Party rally produced 12 extra votes for the Republican party (the question of whether voting matters may be the subject of a later blog post). There aren't many other estimates like this in the literature.
There are many reasons the Tea Party estimate might be an over-estimate for a standard protest, even more so for a large one. For one, the Tea Party protests were fairly small, so an additional person likely yielded larger returns. For two, there's a case to be made that the Tea Party protests happened at a favorable time politically with the pendulum swinging back from extremely large expectations for the incoming President.
So let's take that estimate and divide it by 10. Suppose each person at the People's Climate March produced an extra 1.2 votes in favor of climate action. That's 360,000 extra votes for climate action. Some very rudimentary back-of-the-envelope math using estimates by Nate Silver of the chance that a vote swings an election yields an estimate of a .6% chance of swinging a Presidential election. If swinging the election improves the chance of climate action by 50%, then this march would increase the chance of climate action by .3%. Now if we use as a ballpark estimate the EPA's estimated net global benefits of climate regulations ($67 billion), this march would, on expectation, yield an expected $201 million in benefits - enough to save 60,000 lives.
Many of my assumptions may have inflated this estimate - chiefly, the assumption that the likelihood of each vote swinging the election is independent. I also based each person's wage on the minimum wage - clearly many people will earn several times the minimum wage. On the other hand, one could argue that I made a conservative estimate of individual impact, and that I assigned to each marcher the average likelihood of swinging an election, which should underestimate the impact since marchers who are from swing states, even if a minority, have a higher chance of swinging the election by more than half an order of magnitude. If the march had 1/200th the impact, it would still outweigh the opportunity cost.
There are some further problems, though. We just looked at aggregate or average impact, rather than marginal impact. It is likely that the 300,000th marcher does not have a marginal impact equal to the average impact. The relationship between marginal impact and number of marchers is quite unclear. It seems most likely to me that marginal impact would have an S-shape: protesting by yourself or with a few of your buddies likely has very little impact because of the strength (or weakness) in numbers. An additional person would probably do much more good for a small- or medium-sized march.
Given this, it seems to me to be roughly a toss up that an average person in the People's Climate March would have much of an expected impact, let alone a high-impact person with potential for higher wages and a steeper opportunity cost. But this march was likely not all that high on the effectiveness scale. For a medium-sized march around a potentially higher-impact issue like, say, open borders or animal agriculture, it seems plausible to me that attendance at a march would be high-impact. Given that we are habit-forming creatures, I think an effective person ought to make a habit of showing support for small- to medium-sized protests around highly important causes.
The case is stronger as one moves higher up on the collective action ladder. Organizing a protest, or helping to organize one, can mean getting many more people out. The opportunity cost is of course larger as well, but turning out a large enough number of people with a fraction of your effectiveness can create a multiplier effect. People within the effective altruism movement have pushed for more movement-building and advocacy for their multiplier effects. There are possible (and promising) alternative proposals to political protests - pledge parties to pledge to donate 10% of one's income with Giving What We Can, for instance - but these seem better for consolidating and utilizing a community than building one. There is something about the raw emotional effect of being part of a crowd united around a cause that can change people in a way more coolheaded activities cannot. Scholars who have studied protest movements speculate that this psychological effect is what helps generate and sustain activists. Again, whether I can have a big impact by organizing collective action depends quite a bit on my own attributes. But given that one of the most vital ingredients in a protest is the structure that transforms it from an event into a movement, if I have this ability, I could be doing significant damage by sitting out.
At the end of the day, the question of collective action and its importance comes down to the question of emergence. Many world-changing events have been caused by masses acting together. Few world-changing events have been caused by individuals acting alone. We are individuals, and we cannot directly control anyone but ourselves. But when we look only at the visible results of individual actions, we miss the more diffuse effects our actions have on those around us - the way our actions spread and shape social norms. When you look at the effects of people acting together, though, mass political action may be more effective from a rationalist perspective than it seems at first.
Update: Following dialogue with critics, I was changed my mind on the above post: I was persuaded that participation in large marches on causes that are not the most-pressing does not compare favorably to other effective altruistic endeavors. For smaller and medium-sized protests on causes that are more pressing (likely by orders of magnitude), I believe my above assessment still supports protests and collective action as effective endeavors.