On the surface it looks like any other supermarket. Fluorescent lights reveal shoppers pushing carts along aisles stocked with the usual supermarket fare - dairy, meat, produce, canned goods, frozen foods, household items - and standing in line at checkout counters.
There the resemblance ends.
The sharp-eyed observer notices a lack of candy and other impulse items at those checkout counters, and he spots stacks of a newspaper called Co-op News, free for the taking.
Originally a response to the depression of the 1930s, the Consumers Cooperative of Berkeley Inc. may be the nation's largest food cooperative.
In 1936 a group of beleaguered families formed a buying club. Almost a half century later that club is a network of 11 stores throughout the San Francisco Bay Area. Eight of the stores are full-service supermarkets (most have pharmacies, coffee shops, and health food sections), two are hardware/wilderness/garden supply stores, and one is a natural food store.
With more than 100,000 members and annual sales of $73 million in 1982, the Co-op provides Bay Area consumers with a viable alternative to profit-oriented stores.
Perhaps the first thing people notice at a Co-op store is the prominently displayed suggestion box and bulletin board.
''Your ice cream freezer case with the Valley Gold All Natural Ice Cream is still (after many months) not freezing the stuff,'' one handwritten note says. ''What's happening?''
A handwritten reply is attached.
''Our freezer is at -40 degrees F. We will ask our home economist about the all-natural ice cream to see if the item is difficult to keep frozen. Thank you.''
A professional home economist visits regularly to answer shoppers' questions on nutrition, food preparation, storage, household management, and budgeting. Consumers can also ask questions by phone or by leaving a note in the suggestion box. Answers are also provided in the weekly Co-op News.
Other services offered by this ''uncommon market'' (as it is advertised) include a credit union, discount travel service, a knife sharpener, legal services, health insurance plan, classes and seminars, discount coupons, weekly specials, a community bulletin board, and direct farmer-to-store produce bins with extra low prices.
Some services, such as the credit union and discount coupons, are available to members only. But many are for anyone, and anyone can join for only $10. Membership is retained by shopping at Co-op stores or by purchasing an additional $5 share each year.
Shoppers, whether members or not, are surrounded by advice and information in the form of helpful staffers, signs, and displays.
''Would you feed your child candy for breakfast?'' a sign in the cereal section asks. ''Many 'cereals' are more like candy than cereal. Pre-sweetened cereals usually contain 30 to 50 percent SUGAR.''
The shelves in that section are color-coded. Shelves lined with green contain the most nutritious cereals; those lined with red, the least nutritious. All the popular brands are there, but the consumer can make an informed choice - without reading the minuscule print on the labels.
A permanent ''life line'' display features low-cost nutritious foods on sale, budget menu ideas, and recipes.
Another display put up by the home economist recently showed how a national brand of baking soda has been repackaged as everything from refrigerator cleaner to flea powder for cats. Each package was priced higher than the regular box of the same brand.
Next to these was another box simply labeled ''baking soda.'' A sign described the many uses of baking soda and the money to be saved by buying the generic rather than the national brand.
''I was dumbfounded to find a store urging me not to buy,'' member Richard Pearlman says. ''That's one of the reasons I joined.''
Prices are competitive with local chains but, say advocates, the overall shopping basket costs less, particularly for shoppers who take advantage of the Co-op's alternatives to national brands.
Those alternatives include generic products, Co-op labels, and items that are sold in bulk.
During a recent visit to one of the stores, a giant 42-ounce box of Quaker Oats was selling for $1.99. A Co-op label 42-ounce box was $1.75, and generic was $1.43. At the bulk bins, however, a shopper could buy rolled oats, either quick-cooking or old-fashioned, for 45 cents a pound ($1.18 for 42 ounces).
A variety of beans, peas, rice, grains, pastas, flours, and even popcorn is available in bulk at some Co-op stores. Signs on the bins help shoppers get the most nutritional value for their money.
Another way cooperating consumers look out for their interests is through consumer advocacy at the local, state, and national levels.
According to Co-op education director Lynn MacDonald, the Co-op challenged California's milk price controls in the mid-1970s by selling milk for less than the minimum price standard. The Legislature struck down the law.
''No other store would do that,'' she says. ''A large chain has too much to lose. It gets profits from all levels - production, wholesale, and retail.''
Co-op activists also testify as consumer advocates at state and federal hearings.
''It adds a lot of credibility when a consumer advocate wh m erates a functioning business testifies,'' Ms. MacDonald says. ''We face the same problems as other business, and we know what can be done.''
Over the years the Co-op has had to deal with many business problems. Most recently it experienced a significant drop in patronage leading to the closing of three stores in the past two years.
The Co-op's response to business problems is dramatically different from that of a conventional business.
A democratic institution, the Co-op's basic principles include open membership and ''one member, one vote.'' (Most corporations issue voting privileges according to the number of shares held.)
While corporate stockholders are usually interested in maximizing the profits they make on an initial investment of capital, Co-op members are interested in maximizing their benefits as consumers.
Profits, when there are any, are either used to provide more consumer services for all, or are paid back to members on the basis of their purchases during the year. Patronage refunds, however, are usually too small to be significant to the individual member.
Policy decisions are made by a nine-member board of directors, elected annuall by Co-op members. The last election, held in February, changed the board's composition and, consequently, the direction of the cooperative.
The new board has already begun to implement an aggressive program to attract new members and reactivate old ones. The first step has been to lower prices at the Co-op's higher volume stores. If successful, the board has promised to lower prices in the remaining stores.
Another indication of change was a membership survey in a recent issue of Co-op News. Members were asked to rate various consumer services, ranging from discounts to in-store child care, in order of importance. Increased employee input in policy decisionmaking is another way the board hopes to revive community interest in the Co-op.
In keeping with their name, many co-ops cooperate with one another. The Berkeley Co-op is part of a large network of Bay Area cooperatives in the fields of travel, book sales, organic foods, transportation, funeral services, legal and health maintenance services, insurance, and housing.
Although nationally, cooperative supermarkets and food stores are relatively rare next to the big chains, they can be found. AccOdino to author and longtime co-op activist Robert Neptune, the largest supermarket in Chicago is Hyde Park Cooperative, established in the 1930s.
Five supermarkets and Scandinavian Furniture Stores in the Washington, D. C., area belong to Greenbelt Cooperative, Ms. MacDonald says. They do $23 million a year in food sales alone.
''In the Midwest - in Wisconsin, Minnesota, Michigan - there's a network of small co-ops that were started by the Scandinavian immigrants there,'' she says. ''In fact, co-ops account for 20 percent of retail trade in Sweden, and our own Co-op was started by Finns.''
Nationally, the Berkeley Co-op is affiliated with Universal Cooperatives in Ohio. Universal owns the Co-op brand, helps coordinate cooperative buying, and negotiates national purchasing contracts. It does an annual business of $200 million, mostly in farm supplies, Ms. MacDonald says.
In addition, the Co-op is associated with the Cooperative League of the USA, which represents cooperative interests in Washington and also represents American cooperatives in the International Cooperative Alliance.