If a business can't handle the added expense of maternity leave, I would venture that that business is not socially useful enough to stay open.

Good thing it's not your call. You'd cause a fair amount of misery. And of course it's only minor friction-type costs that are borne by the business. The major costs are borne by the employees. Do you also want them to go out of the business of selling their labor if they "can't handle" the additional expense?

Again, the economy should work for us, not the other way around.

The economy doesn't work for anyone, nor anyone for it; it's simply a by-product of the sum of transactions between individuals.

No, because natural disaster has only negative effects.

This is both untrue and irrelevant. For one example, a heavy snowfall that damages fruit orchards may create benefits for fans of winter sports such as skiing, etc. But more importantly, it's the net effects that matter, not whether there is a mix of positive and negative.

Government regulation is intended to have on balance positive effects,

Again, both untrue and irrelevant. Government regulation is intended to get politicians elected [mild hyperbole, please don't feel obligated to refute]. And even if we stipulate that all regulation is drafted and passed with only pure and benevolent intent, it's still results that matter. Intentions don't create jobs. No one cares about intentions.

or something else will change - it's not obvious at all

...and yet you are certain that your proposed mandate will be a net positive. Are you sure you want to assert both that the situation is too chaotic to know what will happen, and that you are confident enough in the outcome to impose your proposal on an entire country?

You talk about compensation going "back in equilibrium" - what is this equilibrium? Won't it change? The world isn't static, right?

Ahh, the good old gotcha-as-argument. Been a while since I've seen that one. Fair enough, I gave you the opening. For "back in equilibrium" read "back to the level it would have reached [non-statically!] in the absence of the mandate."

Also, we have decades of data from other countries that have done this and it doesn't look like what you're talking about actually happens for maternity leave. So there's that, too.

Oh good, I was hoping someone would have this data. Please post your sources.

But please keep in mind that what I am talking about is not catastrophe, but rather net negative effects, maybe large, maybe small. I think it's rather easy to demonstrate that we won't face total societal collapse by mandating paid parental leave. Demonstrating that the net effects will be positive is much harder. For one thing, you can't do a controlled experiment, comparing the effects on a society with the mandate to those on an identical society without it. And comparisons between different countries, with vs. without, will almost certainly have too many variables to control for effectively.

I've given examples from my real-world experience that support my analysis. I don't think you can make a serious argument - based on either theory or data - that employees bear no costs when new labor regulations are imposed. I think that a case can be made that the positive effects outweigh the negative, but so far I haven't seen it. Based on your posts so far I am not sure which of these is your position:

--It's so obvious that the net effects will be positive that no support for the proposition is necessary

--It's impossible to know what will happen because the system is just so chaotic [but we should forge boldly ahead anyway!]

-- All costs will be borne by employers, and if your employer is unable to stay profitable under the new mandate and closes, then you deserve to lose your job. Couldn't have been a very good job anyway, with no paid parental leave.

Maybe the studies you have will help clarify.