High season for spare bedrooms.

• Author: Winter, Mary
• Position: TRENDS & TRANSITIONS

Lodging has been a golden goose for the so-called sharing economy, the system in which people rent items rather than buy them, often directly from the owners instead of companies. In cities around the world, travelers are bypassing commercial hotels and booking private digs--from spare bedrooms in Atlanta to villas in Tuscany--through websites such as Airbnb, HomeAway and VRBO. The biggest, Airbnb, has more than 600,000 listings in 34,000 cities in 192 countries, according to its website.

Renters love the rates--often half those of hotels, or less--and property owners ("hosts") love the extra income. Local economies gain from the boost in tourism, advocates argue.

For the most part, short-term rentals have been unregulated and untaxed, but that's changing. States see substantial tax revenue to be tapped, and neighborhood groups increasingly want more regulation of the rentals, which they complain bring noise and traffic and lower property values. Other critics say short-term rentals displace lower-income families, and that owners of short-term rentals often violate zoning, fire and occupancy codes but are rarely punished for it.

In 2010, New York made it illegal to sublet apartments for less than a month, but State Attorney General Eric Schneiderman says the law is routinely flouted by owners of multiple properties.

Critics of the blanket ban on short-term rentals, however, say it hurts average homeowners--people who could use much-needed cash from letting a room--so in New York, lawmakers this year introduced bills to allow...