Teachers at The Accelerated School, one of Los Angeles' most acclaimed charter schools, have filed to join the local teachers' union. The move bolsters fears in the charter camp of a crack in the dike, beginning last month with a decision by New York City's KIPP AMP teachers to join the union. If the crack is real, KIPP managers appear to be putting out a call for all thumbs. The New York City teachers' union is butting heads with KIPP management, asserting that KIPP co-founder David Levin is unduly pressuring teachers after he issued a warning to them 'to be careful what they wish for.'

Administrators at KIPP and The Accelerated School most likely worry that once local unions get a foot in the door, the schools' hands will be tied. Union supporters have tried to alleviate fears by citing 'slimmed down' agreements as potential models of a new KIPP contract.

The only thin one we're aware of is the pact between the California Teachers Association and national charter group Green Dot Public Schools, an organization which has always embraced teachers' right to bargain. Yet,the guts of that contract have gotten a little thick around the middle in that brief marriage. Blogger Ken Hirsh pointed out in a recent post that Green Dot's current contract is now 60 percent thicker than the previous contract. The increase is thanks to 20 new pages outlining an observation-based teacher evaluation system. The 53-page contract is still a fraction of the 348-page contract between United Teachers Los Angeles and the Los Angeles Unified School District ... but give it time. Few of us can still wear our wedding clothes.

Are ever-expanding contracts, presumably representing new issues that the union wants bargained, inevitable? A quick review of 22 districts with multiple contract cycles in our Tr3 Database says not necessarily so. Those districts show an average reduction of five pages over recent years or a negative 3 percent change. No district shows as large an increase as did Green Dot. After years of fat agreements, it appears many union contracts may be dieting. While measuring changes in page length is not a proxy for the substantive changes they reflect, charters should remember that--historically--once something is in a contract, it is difficult to remove.