I'm going to try to dissect this in parts so we can hopefully settle this without going in circles anymore haha.
""If the tariff wasn't going to increase the price of the iPhone's, there would be absolutely no point in implementing one because the quantity shipped in would not change."
um... yes. exactly. Apple has a set number of iPhones they're planning on distributing, at a set maximum idea price in correlation with quantity demand. also, the tariff increases the COST, not the price. Apple has this system where they massively overcharge what the general populous would usually demand, because they will still have a core following demanding the product."
I think we both agree that Apple has used the MC and MR curves to decide what is the optimal quantity to produce and to produce there and sell at a price where that amount will be demanded but no more. We both agree they are in a market characterized by monopolistic competition, there is no disagreement here.
"With products that have SUCH an occult brand-name following, the Demand curve changes, because you have two distinct groups of demand. Those who demand the iPhone in comparison of other goods, and those who demand iPhones simply for the product. What this does is creates a demand curve that slopes down normally, flattens off a bit, then slopes down the rest of the way. Usually demand curves don't flatten because every change in price comes with a slight change in the schedule of demand, until a threshold is reached where NOBODY will want or be able to buy it. However, this threshold is at a lower price than it is for a large selling base for apple that religiously buy their products, up until even THEY can't/won't pay too high of prices. this flattened area of the demand curve is where Apple sets up their prices - which is why it's ridiculously high at first, but then prices fall as the religious buyers already have their phones, and now they need to optimize to the general populous, which is lower down the demand curve."
I disagree with this assesment, it is contrary to mainstream economic theory concerning demand. Demand curves are always downward sloping, they don't level off at any point. Leveling off would imply that as the price decreases, there aren't any new people who will buy it, and as the price increases, nobody refrains from buying it because of the increased price. There is always someone who will stop buying it when the price increases by the smallest fraction, and someone who will start buying it when the price decreases. Because of this, the demand curve cannot become completely flat, it is always downward sloping, even if that downward slope is quite small. This would appear to be why we come to differing conclusions as to the effect of the tariff. You don't disagree that the tariff will push the MC curve upwards and correspond to a higher price and lower quantity if the demand curve is downward sloping. But you are claiming it is flat at some portion and this is causing the MC/MR intersection to still hit it at the same price point, leaving price unchanged but quantity reduced. I have yet to see a flat demand curve because of what I said earlier about why the demand curve is downward sloping. Do you have a source you could provide giving support for a completely flat demand curve, in monopolistic competition if possible (Since that was what we were discussing, it would be most relevant)?
""I'm telling you it will increase the price of the imported good though, always."
here's the problem, you're assuming Apple is on a standard demand curve. As i stated above, their curve for product demand is much different than standard curves, because of the nature of demand for their product. Thus the COSTS OF PRODUCTION increase, the PRICE will not immediately be affected.
the consumer will be just as bad off because Apple's prices are set, but after a year the price will fall down because the demand at high prices by the religious followers (just a term lol) will lower, and because of the tariff Apple might make that lowered price a bit higher than they originally intended.
Alternatively, they might have too much stock and try to dump inventory at lower prices! The tariff has much less of an immediate effect, and because of this lag, consumers are less likely to be hurt (as much)"
See above.
""But, this has nothing to do with supply side economics which is a macroeconomic model of fiscal policy."
of course not, for this one scenario it is clearly not about supply side. My main argument with supply side economics are that governments overestimate the flexibility of corporations who get more money, because if Apple suddenly has 1 billion $ extra, they can't just make 1 billion $ more iPhones:
because the demand curve is already optimized, and you'd only have overstocking in inventory. for seasonal goods such as iPhones, these policies would not drastically affect GDP. sorry for getting off track with that comment."
You're absolutely correct, that's why I said the effects of Supply Side are there but minimal when it comes to affecting output/employment in my original explanation. I don't know your background and wanted to just give a brief overview in case you weren't already aware of the theory's theoretical underpinnings, but it seems you are. We agree here.