Effective Altruism (EA) is a movement trying to invest time and money in causes that do the most possible good per unit investment. EA was at one point called optimal philanthropy).

The basic concept behind EA is that you would really struggle to donate 100 times more money to charity than you currently do--but (assuming you are approximately utilitarian), spending a little time researching who to donate to could have an impact on roughly this order of magnitude. The same argument works for doing good with your career or volunteer hours.

Concepts

Despite a broad diversity of ideas within the EA community on which areas are most pressing, there are a handful of criteria that are generally agreed make an area potentially impactful to work on (either directly or through donation). These are:

The area is generally neglected, that is, it has capacity for more support either financially or in terms of skills
The area has the potential for large impact, either in human lives saved, animal or human suffering alleviated,
catastrophic crises averted, etc.
The area is tractable-- it is a solvable problem, or is solvable with minimal resource investment (relative to other
problem areas)

From this, we can see a vast number of charities do not meet all or indeed any of these criteria. A major issue with EA is that some areas are much easier to track progress in than others (think tracking the cost per life saved of malaria nets vs existential AI risk, for instance). What is clear, however, is that some of the more effective charities (of those which are easy to track) have far more benefit over the average charity than people think-- perhaps as much as 10,000% as effective.

A large portion of the EA community are by and large, longtermist. This refers to the idea that, if there are many future generations (100s, 1000s or more), and their lives are as valuable as ours, then even very small impacts on all of their lives-- or things like moving good changes forwards in time or bad ones back-- far outweigh impacts on people who are currently alive. Because this concept is less broadly-accepted than charity for currently-alive people, longtermist solutions are also generally considered to be neglected. Longtermist interventions generally focus on S-risks or X-risks.

Examples of longtermist interventions include AI safety, pandemic preparedness, and nanotechnology security. Ex...

Past and Future Selves