>But at their peak, three thousand children a year were visiting emergency departments for suspected magnet ingestion (a number which declined after the CPSC ban).[1]

Several points:

1. Suspected magnet ingestion =/= magnet ingestion. I believe we should stop here, however:

2. Of course a total ban on sales (which was in effect for some time) would decrease this number, but

3. So would improved packaging and public education campaigns on the potential dangers of the product, which were happening at the same time, and

4. If you actually read the paper, they observe that the reduction in the suspected ingestion cases was not that large: from 8,326 to 6,260. Perhaps you should include that in your cost function.

5. Also from the paper: 86% of the kids were "treated and released from the ED or examined and released without treatment"

To put the nail in the suspected coffin, one should go and read the article you referenced: [SciHub link][1]:

>Subjects from 0-17 years old were included using a primary search term for diagnosis of “ingested object” from the time period of 2002-2015. Cases of ingested objects were classified as “suspected magnet ingestion” (SMI) if the term “magnet” appeared anywhere in the narrative section of the database.

Meanwhile, a million kids ended up in emergency rooms from trampoline-related injuries over a decade[2], and no one bats an eye.

[1]http://sci-hub.nu/10.1097/MPG.0000000000001830

[2]https://www.linkedin.com/pulse/7-terrifying-statistics-tramp...