RE: Should Americans always "Buy American"?
You are only "wrong" to buy NZ if you are passing up a better deal on a product made somewhere else. Often, people choose to "Buy American" even though they know the item costs more and may be of lower quality. You may be "wrong" in terms of your own financial best interest, but that's not the only factor that goes into how you, personally, determine value. And I believe that's okay from a philosophical point of view.
But if you're buying a higher-priced item made in NZ, and that behavior is repeated by others in NZ, economy-wide, it can actually hurt the economy as a whole. Any time you're rewarding the producers of lower quality or higher price, you're sending false or bad signals into your economy. And you're doing it with less purchasing power. To answer your question, yes it will reduce unemployment for the people you buy from, but what you don't see is how your lessened purchasing power affects other members of your local economy.
Bottom line: if you have non-economic reasons to buy NZ and you feel better doing that, then do it. But if you're only doing it because you think it will help your economy, then don't bother.
I was thinking this through some more in the shower, and realised that part of the equation that I hadn't been considering is what I, as a consumer, do with the savings I made. If I use it to buy free range eggs, instead of supermarket, for eg, I am using it to reward someone in NZ who shares my values. Thanks.
And on another note, check out @lukeofkondor - you might like his fiction too
Yes, if you want free range eggs, you value that method of production much more than a savings you might enjoy on factory farm eggs. Which is why economic considerations aren't the only variables we use when determining how we value a product.