It's not hard to jump on the bandwagon of disparaging Walmart. But this doesn't need to be about Walmart specifically. Rather, it's about what this kind of economic transaction does to people in a community.
So, if once we were all "local" that meant we lived our lives among people we knew as part of our daily routines--shopkeepers, bankers, school teachers, etc.--we knew these people and when we asked "how are you today" we might have gotten an answer other than "fine, thank you". We might have heard about sons and daughters, hopes and dreams, bad things and good things, and we likely would have cared.
Now that's sentimental of course--or at least a sentimental representation--but it's leading to my point. We are no longer interested in anyone else's world.
A big box, one-stop shop that is located to be geographically central among many smaller communities decimates all local stores and draws all "shoppers" into it. This is a fact.
The real damage here is not just loss of real local economic health; it's the loss of community. It's the loss of care. It's the change from people as citizens to people as consumers.
The benefits of this consumer largesse: access to "goods" no matter how useless or wasteful--access to "novelty"; access to the next thing; the "better" coffee-maker or vacuum; the 24 pack of toilet paper; the big bigger biggest television...and on and on.
The disadvantages: loss of local transactional relationships--ie, buying products from local stores; less local knowledge of community living--with less reason to daily interact with other citizens there's less information passed via word of mouth; more interest in the "stuff of consumption and what it means for YOU; more ways to spend your money (ie, more ways your money is "coerced" or seduced out of your pockets; less interest in local politics as a definition of the "good life" locally--more interest in "economic" and tax issues.
Further there is a loss of community--real person-to-person community. One becomes detached from physical life. One is less oriented towards involvement. One is less concerned about political life and how it affects one's day-to-day UNTIL the worst has happened and local school programs are being cut. In other words, you weren't even aware there was a problem. In other words, your detached brand of life has left you a "subject" who is managed by others. And when they screw up, what's your recourse?
We are useless citizens now. We are no longer self-governing. This is the consequence of the economics of more represented most glaringly (and most powerfully) by that damn bouncy smiley face cutting prices by 42 cents. What a great savings.