dollar exchange rate - random number generator plus hyperbole

Photo dollar exchange rate - random number generator plus hyperbole

So. The dollar exchange rate according to really still exists and it makes sense to track it. But... everything is very complicated.

1. The minimum Ali dollar exchange rate for today (March 25) is 77.5365. (And that's exactly how it is set - with an accuracy of four decimal places).

2. The dollar exchange rate "for non-logged in", it is also the maximum rate (what you see when you go to the product pages in incognito mode without logging in) is the minimum rate + 5%. Those. today it will be 77.5365 * 1.05 = 81.413325

3. Intermediate rates are the minimum rate +1%, +2%, +3% and +4%. Those. here is the full table of possible courses to date:

77.536500 +0% min 78.311865 +1% 79.087230 +2% 79.862595 +3% 80.637960 +4% 81.413325 +5% max

4. "Main" course, i.e. the exchange rate that we see most often is +2%. And the courses +1% and +3% are either not used at all, or are used vanishingly rarely.

5. For each account, one of the courses is attached to each product - from min to max. More precisely, the rate is tied not even to a specific product, but to a specific sku. (Remember, after all, that there can be several prices on one page - depending on the configuration, color, etc.?oh "sub-product" has its own number - sku). It's rare, but I've seen it. I didn’t meet - I wouldn’t believe it.

6. The rate linked to sku may change during the day. Or maybe not change.

7. By what principle goods are assigned this or that rate is a great mystery. It has been established that within one account at the same time there can be different courses. Apparently, the probability of assigning one or another course somehow depends on the properties of the account. But still, in the vast majority of cases at the same time in the same account for mostThere will be one course for two goods.

But they were still flowers. Berries will be in front.


When I began to delve into all this thoroughly, one little thing was very embarrassing. Here you have a certain product in which a dozen or two sku with different prices are buried. You calculate the dollar rate for each sku and are surprised to see that it is slightly inaccurate. It seems to be mere pennies there. But the pennies are too big to be explained simply by a rounding error.

And then I suddenly found a very strange product with a lot of sku inside. MinimumLet me remind you that the current exchange rate for today is 77.54 (and the main one is 79.09). And this product has the cheapest sku today for sale at the rate of 75.74 - i.e. less than the minimum! And the most expensive - at the rate of 77.52. And the more expensive sku is, the higher (i.e. worse) the rate!

Then I found a few more similar products (they are quite few, but they are found). Then I came up with the idea to build a graph of the dollar exchange rate versus the dollar value of sku for one such product. This is what happened:

Great graphics. Very even. It's not very obvious from the picture, but this graph comes offsya. The formula is simple: exchange rate = k/usd + constant. Hyperbole... Haven't seen you for a hundred years! That's how the institute graduated... Here k is a certain negative coefficient. And the constant... In this case, this is our main rate, i.e. 79.09.

I.e. what we get. This product (i.e., the sku group) was assigned a dollar rate from the available set (from min to max). In this case, the main course. But on top of this, they additionally imposed a function. And in the limit, at an infinite price of goods, the real exchange rate will coincide with the main one. And at low prices, it will be different. Sometimes - strongly. Sometimes - not very�.

In most cases, the coefficient k is negligible, so we just don't notice it. And yet, as far as I can see, this coefficient can be both positive and negative. Those. convergence can go both from above and from below.

I understand everything. Except one. Why?

P.S. your rates. How many days does it take for AliExpress programmers to come up with something new?

I am from Mumbai, India. I write about gadgets and novelties of mobile phones. My profession is a telecommunications engineer.