Because each step in the food chain involves energy loss, the shorter the chain, the fewer plants need to be killed to support you. Thus being a vegetarian saves plant lives too.

Plants and intelligence-- plants do a lot more problem-solving than you might think.

I'm trying to cut down on soda intake. I've gone down from 1 bottle of coke per day down to maybe 3 cans per week. However, I do work night shifts at a bar so there's the temptation to sneak a glass or two from the taps for the caffeine boost, to get me through the night.

That's like saying that being a computer programmer is immoral, because if everyone would become a computer programmer, no one would cultivate food, and within a month the humanity would vanish.

It's possible to make a more complex algorithm saying that those who have a comparative advantage in computer programming should become computer programmers and those who have a comparative advantage in cultivating food should cultivate food. This way humanity can survive.

Analogically we should be thinking about consequences of a world where people with a comparative advantage in donating don't have children and instead donate the money to efficient charities, and some other people have children and ensure that humanity survives. -- There are some things that could go wrong in that scenario, but it's not that trivially wrong.

(Also, it is important to note that most people don't behave according to Kant's rules, so even a strategy that would maximize global utility if everyone used it, is not necessarily the global utility maximizing choice for an individual in real life.)

EDIT: I am not deeply familiar with Kant's philosophy. It just seems to me that it makes sense to seek an algorithm that maximizes global utility when used by everyone, but it would be stupid to require that the algorithm produce the same output for everyone. If two people have different comparative advantages, they can both use an algorithm "do what is your comparative advantage and trade with the other person", and yet their behavior will not be identical. Children are valuable, in my opinion; the topic of this discussion is that maybe some people can create a lot more value by doing something else.

Kant's Categorical Imperative is directly applicable to this problem.

Will Kim Dotcom be there?

But what if you could obtain the nutrients available in vegetables through other means?

Per the vegetables question: what should I eat?

Instructors differ significantly from one another in terms of their quality of teaching (human capital + consumption value) and ease of grading (signaling). I'm curious here about the extent to which LessWrong readers think variation between instructors for similar courses compares to variation between institutions. For instance, how much does variation between instructors at Harvard compare with variation between UCLA and Harvard?

I had a few great professors (e.g. this guy), and mostly good ones, at De Anza College, a community college in Cupertino, California, to the point where I was a bit disappointed after transferring to UC Berkeley.

By this reasoning, if the child is 5 years old but the world is going to be hit by an asteroid tomorrow, unavoidably killing everyone, it would be okay to be cruel to the child.

To save the original idea, I'd suggest modifying it to distinguish between having impaired ability to come to agreements and not having the ability to come to agreements. Children are generally in the former category, at least if they can speak and reason. This extends to more than just children; you shouldn't take advantage of someone who's stupid, but you can "take advantage" of the fact that a stick of broccoli doesn't understand what it means to be eaten and can't run away anyway.