Ecommerce product rankings tank when procuct out of stock

[HDPHNS]

When checking our weekly ranking update this morning I noticed that several products where down 2-3 pages (or even dropped from the first 50) from last week. Looking through these products, they share one common trait: these pages are for products that are no longer available or are temporarily out of stock (and have been for the last few weeks).

I understand Google is looking at bounce rates, but do they also looks at our website (or Schema markup) to see if the product is in stock or not? We also use Google Shopping to they should have a pretty good understanding of our stock levels and the general availability of our products.

If it's just a question of bounce rates, we could switch to pre-orders for our products (we don't take any order for out-of-stock products at the moment) or we could offer the more expensive versions with a discount.

If Google is looking at inventory status, we could disable this to keep ranking high and increase our search presence. Any drawbacks on this?

Just getting back in the SEO-game after a focus on the business processes so I could use some help here. We seen great improvements where we've stepped up and created great product descriptions, but it is really disheartening seeing products get dropped so easily.

[GlobeRunner]

HDPHNS, it's quite possible that Google is doing that on purpose--that they see the product is out of stock so they don't rank it as high. Google wants to provide a good user experience, and it would be frustrating if someone went to Google, did a search, went to your site, and found that the product is out of stock.