Looking at business life spans.

• Position: DRAWING CONCLUSIONS - Brief article

The Mile High City and much of Colorado may be booming, but Denver small businesses have a slightly below-average life expectancy of 4.9 years, according to research by the JP Morgan Chase Institute, released in July. The average lifespan of a U.S. small businesses is 5.3 years, according to the study, "Growth, Vitality and Cash Flows: High Frequency Evidence from 1 Million Small Businesses."

Of the roughly 20 markets cited in the report, Denver had the third highest share of firms grown with "organic" or limited external financing (56 percent) and the lowest share of financed growth firms (1.6 percent). Nationally, across the spectrum of 12 different industry sectors, the study found real estate firms lasting nine years and restaurants staying in business for...