I think this is going to be hard. I think with things like this you ahve to focus on immediate results, sales at the markets, etc. Maybe sellers at the markets can tell you how important market sales are to their business. I have a hunch that if the sellers charged themselves for their labor many would be in the hole.
Could depend on where you are. We have a small (tiny?) farmer's market in Wayne. A lot of customers are summer people and visitors. They tell me that people going somewhere else will stop by on impulse and buy something.
There is a huge gain in sociability for the town.
I see a few other small business sprouting on Main st and wonder of the Market is part of this -- would have to interview the owners.
There is no way that a weekly farmer's market could materially move the needle on diets and health.
Our son is a chef near Blue Hill, where there is a year round farmer's market. That could be quite different.
I think farmer's markets may be more a cultural phenom than an economic or health one. I would resist trying to "metric" this phenomenon, at least w/o knowing a whole lot more about it . there is an issue of scale-- both at the community level and the enterprise level.
Also, I note that a lot this sort of activity, incl community gardens, gets subsidized a good deal, which is fine but kind of muddies the waters as to their actual sustainability. Are we measuring the effect of the activity itself, or that of the grant money being respent in town?
My preferred strategy would be some deep, unstructured "key person" interviews first .. you could collect a lot of anecdotes and examples that together would be much more compelling than weak "metrics".
Glad to brainstorm all this sometime over a burger or something,
Ever talk to Stew Smith about this? Direct sales is clearly going to be strategic for many small farms and ag mini-businesses. He has done a lot on this.
I will have to ponder the notion of anecdotes to see how this might rolled up. It speaks to the unique position of each farm and its relative impacts on local communities.
The answer to your question is highly contextual - metrics relevant to a developed economy may not apply to a subsistence farmer and farming community. The answer also depends on the degree of congruence between individual goals (and achievement/impacts) and community goals/achievements/impacts - I suspect you need metrics derived from interviewing' individual farmers AND metrics derived from a different process designed to elicit community impacts (desired or otherwise), perhaps focus groups. If I recall correctly, the B&M Gates Foundation has put a lot of effort into developing methodologies to be used to develop such indicators. The rural development literature has quite a bit on this topic.
I agree with your key points: that answer is contextual in part depending on the socio-economic context, across a gradient of small subsistence farm to large commercial farms. My context is small to large commercial farms. We have conducted three community workshops. For community members, the biggest concern was community health (principally impacts to water quality) and nuisance (mud on roads from tractors moving around and odor from manure) followed by amenity issues (visual appeal of ag. in the community and access to land for recreation).