FOR FOUR DAYS in early June, thousands of booksellers mushed through Chicago's convention center, wearing buttons that said "ERA Yes" and "Punish Me With Kisses" and "Sicut Lillium Inter Spinas" and "The Sky's the Limit." They munched on popcorn and cookies and little bits of fried shark. They had their pictures taken with Darth Vader and with a 6-foot green felt frog. They had silhousettes of their profiles cut and they dropped their names and bookstore affiliations into raffle boxes to win a teddy bear or a trip to Ireland or a TRS-80 computer. r

They rubbed funnybones with former president Gerald R. Ford (or at least with his security men) and with the likes of Shelley Winters, Merv Griffin, Margaret Truman, Gloria Swanson, Billy Martin, Victor Borge and Mike Farrell. They lined up to get autographs from James Clavell and Maurice Sendak and Brooks Stanwood and to pick up the latest B. Kliban Cat shopping bag. They went to screenings of Urban Cowboy, The Shining and Empire Stikes Back. They went to parties for Mary Higgins Clark and Erica Jong and The Wind in the Willows.

But most of all they came to see the book industry's entire fall 1980 publishing schedule spread out like a banquet for them to gorge on or nibble. It was the annual American Booksellers Association Convention, the largest and most important meeting of its kind held anywhere in the world.

Compared to last year's meeting in Los Angeles, which 20,000 people attended, Chicago was a more subdued, less glamorous and much more cautious convention. It was safe; there were no surprises. Attendence was down; the final figure given out by ABA officials -- 17,000 -- was heard with skepticism by everybody I talked to, possibly because Chicago's McCormick Place convention center is vast enough to displace reapers, combines and harvesters, and we humans appeared smaller and fewer and more scattered. But traffic was lighter than in recent memory.

For the first time the convention was not held on the three-day Memorial Day weekend, and the potential loss of an extra day of business on the home front, combined with the rising cost of gasoline for booksellers who would normally drive to the convention, combined with the hundreds of bookstores that went out of business since the last convention, probably accounts for the drop in booksellers.

Buying appeared to be down too, and again the economy was to blame. With rising inflation hitting the business hard, publishers and booksellers are looking twice before spending. The publishers shucked and jived a lot less at this convention. Generally speaking their booths were less expensively elaborate; their giveaways fewer and less costly (it was back to buttons again, for the most part, and buttons have been boring since 1975).Buying was not only down, it was cautions. The watchword was product identification. Bookstores are investing most heavily in authors, not titles, authors guaranteed to pay off, as proven in the past.

I spoke to a large number of booksellers, both from the huge chains and from small independent mom-and-pop operations. What were they buying? "Well, the Michener, of course," said almost everybody in exactly those words. Followed by "the Avery Corman and the Erica Jong, the Sidney Sheldon, and the Ken Follett, the Stephen King, the Mary Higgins Clark . . ." Safe investments in blue chips and utilities. Another reason for smaller orders on the convention floor is that booksellers who underestimate the selling power of a title can always restock locally from jobbers and wholesalers.

The convention floor also appeared emptier because there were many fewer literary agents and film people, who always bring with them hustle and the whiff of glamor that surrounds big deals and big bucks. At the convention last year in L.A. they dominated the floor, all those transplanted New Yorkers from Movieville in their tans and Lacostes, looking for The Deal.

The presence of subsidiary rights people -- not only those who work for publishers but also literary agents from both coasts and eager story editors from the studios -- has become an increasing irritation to the booksellers who are angered because they have been elbowed out of the way at their very own annual convention. This year rights people were barred from the floor on opening day, designated "Bookseller's Day." Most of the rights people stayed away. Their absence accounted for a lot of the somnolent solemnity of opening day. Still, rights were traded. Nothing prevented the foreign publisher-exhibitors from dealing in rights. And they did.

What did best at this new-book convention were old books and nonbooks. The booths doing the briskest business were the ones selling remainders, publishers' overstocks. With cover prices of new books escalating, it's logical that stores are checking out 1978 books at 1953 prices. Sidelines did well too. Calendars, stationery, Snoopy and Holly Hobbie and Cat tschatschkas -- the nonbook items that get high turnover at the cash registers. Some of the stuff was outstanding. The Miss Piggy calendar for 1981 is a knockout and should sell in the trillions.

Another issue causing friction was aired at the convention -- aired and tabled. The Women's Media Group of New York set up a table at the entrance with petitions protesting the holding of this year's convention in Illinois, a state that has not passed the Equal Rights Amendment, and calling for a boycott of the ABA's convention if it is held as presently planned in Atlanta, since Georgia is also an unratified state. Literary agent Elaine Markson, who was in charge of the petition, told me they had collected about 4,000 signatures and $500. The issue was raised at the ABA business meeting, but the resolution to hold all future conventions only in states that had passed the ERA was tabled. Maxwell Lillienstein, attorney for the American Booksellers Association, advised its membership that they were open to possible litigation if the association participated in an economic boycott of Atlanta. This is an issue that, although tabled, will be raised again.

The death of Henry Miller saddened the publishing community even though the 88-year-old Miller had been failing for some time and died peacefully. Noel Young of Capra Press in Santa Barbara was the last of Miller's publishers, and Young had been working on the publication of The World of Lawrence: A Passionate Appreciation, which Henry Miller began in 1932, only two years after D.H. Lawrence died. The manuscript and never been published in its entirety and Miller was looking forward to the event with great eagerness. "I've been waiting 45 years for this, Noel, and I'm not going to be around much longer. Can't you hurry it up?"

Young pushed the date for finished books up from late July to mid-June and put in an extra effort. But the day that the first books reached Young in Chicago -- Saturday, June 7 -- was the day he learned of Henry Miller's death. Although Miller never did get to hold the finished work in his hands, he did know it was imminent.

Next week, we'll tell you about the brighter side of the convention: the best booths, the hot parties, the pick of the books, the funniest exhibit in history and dinner with Shelley Winters . . . you should have been there.