I have come to suspect such algorithmic pricing “coordination” may be facilitated at the consumer level by sharing of web search results. Recently I was shopping for a circular saw. Eventually to decided on the saw I wanted, and was looking around at pricing. At first, one retailer had the best price, which was $169, $30 off MSRP of $199. Then after searching some more, I noticed another retailer had it for $149, but that was for delivery, and I needed it for a job quickly, so I settled on the first retailer. When I went to the store to buy it, the price ended up being $149.

In this case, this apparent “coordination” worked out in my favor, but the same mechanism could easily be used to raise prices. Either way, if such a mechanism exists, it is troubling.