Once you get away from point of service, I think two things kick in that make it really unlikely that any stage before it would substantially increase the % that goes to labour costs:
1) economies of scale, factory farming employs very few people per pound of meat produced, having been subject to a lot of automation. Likewise, supply chain areas like storage and shipping move a lot of product per employee.
2) 'butchers' and similar jobs are relatively high skill and likely pay above minimum wage anyways. They also have better economies of scale. But at any rate, it's unlikely professional butchers are particularly involved in producing meat for fast food burgers and likely 1 or 2 low wage employees in a factory are doing all the manual labour involved in producing meat for hundreds of burgers.
At any rate, I don't think the null hypothesis can really be that every level of the supply chain has the same level of labour costs.
I think this is natural, as you're always sub-dividing the remaining 66-75% of the pie. Even if you assume exponential decay of labor as a percentage of the remaining cost, it can still add 5-10%, which is a meaningful fraction. I don't strictly disagree with the original post regarding labor not being the lion-share of many businesses.
As a nit to my original post, butchers was more meant to be representative of a class of service that is relied on by consumer-level providers. I think we can agree that it is fair to assume there are more than just first-order workers who make less than $24 a hour in most supply chains these days.
1) economies of scale, factory farming employs very few people per pound of meat produced, having been subject to a lot of automation. Likewise, supply chain areas like storage and shipping move a lot of product per employee.
2) 'butchers' and similar jobs are relatively high skill and likely pay above minimum wage anyways. They also have better economies of scale. But at any rate, it's unlikely professional butchers are particularly involved in producing meat for fast food burgers and likely 1 or 2 low wage employees in a factory are doing all the manual labour involved in producing meat for hundreds of burgers.
At any rate, I don't think the null hypothesis can really be that every level of the supply chain has the same level of labour costs.