Now consider Broward County in 2009. The county, between Miami and Palm Beach, was one of the first areas to shrink  losing 21,117 people from April 2007 to April 2009, according to University of Florida data  and its experience offers a glimpse of what could be on the way elsewhere.

Hollywood, in particular, embodies what the Sunshine State was and might become. It was founded in the 1920s as “the dream city of Florida” by a transplant from Washington State named Joseph Young who built ranch-style homes. After growing predictably  from 22,978 people in 1955 to 139,357 by 2000  Hollywood has lost 1,562 people over the past year, according to the University of Florida count.

That amounts to only 1 percent, roughly in line with the rest of the county, but residents say their rhythms have already changed. Here and in other places adapting to the end of double-digit growth, the days include less noise, work and spontaneity, and more goodbyes, doubts and fears of the future. It is, by all accounts, a life lived under capacity.

Sandra Woodward, 25, grew up here, happy and proud. A secretary with dreams of working in education, she said eight houses on her block are in foreclosure. She knows 20 families who have left Florida in the last two years.

On Monday, she waited for her son to finish his first day of kindergarten at her alma mater, Hollywood Park Elementary. About 10 years ago, Ms. Woodward said, gesturing toward the parking lot, temporary trailers were needed, as the school was over-enrolled. This year, the principal counted 469 students registered  124 fewer than the school can handle.

“I used to go up north to visit my family, and they all wanted to come here, to be part of this,” Ms. Woodward said. “Now I’m thinking about leaving, too. It’s scary.”