I'm opining/arguing that if you make this statement:

>The best way to "control" population growth is...

Then provide some level of govt incentive to reach that goal, it's still coercion (or if you prefer, manipulation), even if the incentive is 1st order positive effects, and the stated goal/result is a 2nd or 3rd order effect.

Thinking about it, I keep coming back to preditory lending/selling tactics or dark-pattern manipulation (except the UI is your life choices) as comparisons, but I haven't worked out exactly why, yet, other than it bothers me in a similar way. Moreso, since it's government.

That's a rather strange position to hold. It brings in issues related to both the Prisoner's Dilemma and the Tragedy of the Commons. To whit, each individual reproductive group may desire more offspring, but each successively larger generation consumes more resources. Given a (for the foreseeable future) finite amount of resources, unrestricted population expansion is net harmful to society as a whole, even as large families may be beneficial (i.e. result in greater happiness) for individual groups.

It's a coordination problem. Everyone wants to act in the way that maximizes their happiness/success/utility, but in doing so acts in a net-negative way. One of the premier purposes of government is to solve coordination problems. Why is it unethical for the government to solve this coordination problem?

Or, more concretely, why does my right to have a dozen children trump my children's right to have sufficient resources left to them to live a happy life?

There is no manipulation. You offer better choices to people than they currently have, such as access to good education and tools they are free to use to manage their personal life (e.g condoms). As a side-effect it is expected that the number of birth per woman will reduce over time.

People are free to use or not birth controls if they want or not children, same for the education. People aren't tricked in reducing the amount of children they have. Data in developed countries seems to point that when people are better educated and have the tools to decide for children, they get them later in life and in less quantity (without considering other factors, such as religious communities that have more children per woman than average).

In a sense, law-making is all about providing incentives. How's birth control any different than other aspects of life? I'd say that's a quite broad definition of coercion/manipulation.

That works a little in reverse as well. If you can curb teenage pregnancy you significantly change the demographics of a region and lead to women being the power drivers in a community. It literally reverses cycles of poverty

...and you can only do that with education and contraception, since human nature makes people feel okay to break the rules so long as they aren't being watched. Punishing teenagers for doing teenage things has never worked out anywhere (not sure if that was the intent of your message, but just putting it out there).

Thanks for clarifying, no that wasn’t the intent of the message - contraception and education are key

That's true, but this is also an attempt to a moral question with a pragmatic empirical answer. The problem with this is the data can always change.

How would your opinion change if that correlation were found to disappear in the coming decades? Or if it actually began to reverse (for example as populations shift to being more urban where kids are expensive and access to assisted reproduction depends on wealth)?

I don't know.