How do grape farmers decide whether they sell their grapes as regular grapes, raisin grapes or wine grapes?

They don't have to choose, it depends on what species they are working with. If they want to make a wine they have to plant a wine specific specie, if they want grapes for direct consumption it's a whole other specie.

Vinyards are quite an investment, it takes often more than 5 years to produce anything, so you better be sure that you are working with the right plants!

Also usually the vines are clones (for consistent wine taste) and so you can lose a whole vinyard if that specific individual genus is susceptible to a passing disease (since the clones all have the same genus, they are ALL IN DANGER!!!!)

Source: my uncle was a vinyard owner and farmer in the south of france, we talked about all of this while drinking his coop's fabulous wine)

Farmers seem to be underrepresented on the fediverse.

Different types of grapes are used for different things, but most growers have a plan before they plant grapes. Most produce is effectively sold before it's planted, generally there are contracts that agree to price per bushel, delivery windows, and minimum quality. The price is based on commodity market trading generally. The other option is the farm is part of a winery, so they use the grapes to make their wine or juices.

Farmers don't just grow things and hope to find buyers, they also don't really care what the buyer does with their product.

The difference between wine grapes and regular grapes is the variety. If you've ever heard names like Pinot Noir or Chardonnay, those are not only the type of wine, but also the variety of grape. Those grapes are also typically not very edible. For edible grapes I imagine it works similar to other food production. The farmer sells it to a distributor who in turn sells it to wholesalers who then sell it to stores, factories, etc. Or sometimes the farmer might have a direct contract with a large grocery chain.

What a grape question! There must already be lots of answers on this pressing matter, but ppease don't wine if you don't get the skinmy right away - it's the yeast you could do.

Usually they specialise on either table grapes or wine grapes. The choice is based on previous know-how, familiar tradition, and local consumption patterns; for example if you're in Europe you'll have an easier time selling wine than table grapes, but in China it's the opposite. Then you got to choose which grapes you'll plant, how you're going to prune and "train" them, handling (chilling them for consumption vs. pressing and fermenting them).

I'm not sure but I also think that the local climate plays a bit of a role; more temperate areas will give you more of a choice between planting wine vs. table grapes, while for areas that are too hot or too cold you'll probably focus only on wine.

I don’t know the answer, so I’ll just post this screed from the terrible film “Psychos in Love”.

I hate grapes! I can't stand grapes! I loathe grapes! All kinds of grapes! I hate purple grapes! I hate green grapes! I hate grapes with seeds! I hate grapes without seeds! I hate them peeled and non-peeled! I hate grapes in bunches, one at a time, or in groups of twos and threes! I fucking hate grapes!

I'm pretty sure vineyards grow their own grapes. They starve the grapes making them sweeter and smaller for best fermentation.