Unfortunately, economists doubt whether that other industry -- construction -- really counts when it comes to economic diversity.

An Industrial Diversity Index compiled by Applied Analysis and Urban Environmental Research LLC said that of Clark County's 872,300 jobs, 266,500 are in leisure and hospitality. Another 105,200 are in business-support roles categorized as professional and business services.

The next significant category is construction with 103,600.

While it's a lot of jobs, Jeremy Aguero, principal of Applied Analysis, said it's not the sort of economic diversity that adds new industries to the employment base and serves to stabilize an economy.

"That's not the traditional definition of economic development," he said. "Construction is an outcropping of growth in every other industry. You can ask: Is it really an industry unto itself?"

Keith Schwer, a UNLV economist and director of the Center for Business and Economic Development, agreed.

"It's not usually what we consider diversification," he said, explaining that diversified companies are typically "export-based."

"That is, the goods and services go out of the economy and the money comes back in," Schwer said. "And construction tends to be one time (projects)."

Still, Aguero said the effects of construction strength are positive.

"It's not that it's a bad thing," he said. "Construction represents a lot of jobs for a lot of people."

The employment figures in the index represent local statistics through July. Just a year ago, construction jobs employed 90,600 workers.

Based on the index, the local leisure and hospitality industry is three times as large as the national average. Construction is twice are significant in Las Vegas.

Manufacturing, which employs 24,700 workers in Clark County, is just 25.9 percent of the national average for that industry. The information industry, which has become a key factor in the national economy, is less than 50 percent as significant in Las Vegas than the U.S. average.

Overall, the Clark County diversity score came in at 61.2, well below the national average of 100, the index said.

The score makes Southern Nevada one of the least diverse economies of its size in the nation, the index report said.

Aguero compared the local economy to the government-focused economy in Washington, D.C., Wyoming's coal industry, Alaska's oil and gas industry and the tourism industry in Hawaii in their narrow economic focus.

Still, he said, the local economy has been "resourceful and resilient."

"There are dangers to that (limited diversity)," Aguero said. "But granted, we've been on the right side of that for a long time."

He also pointed to emerging economic development successes, including the recent acquisition of Las Vegas-based software company Systems Research and Development by international power IBM. He also pointed to the Nevada Cancer Institute and the World Market Center.

The cancer institute, Aguero said, could be the foundation of a growing health and medical services industry. The World Market Center, he added, makes sense since it diversifies the economy while complementing the existing tourism industry.

"It's almost the perfect diversity," he said.

Schwer also said that economic development is best examined over an extended period of time, pointing out that Silicon Valley sprung up around Stanford University after World War II and that the gaming industry in Las Vegas has taken many decades to reach its current level of maturity.

"All too often when we look at economic diversity, we take too short a time frame," he said. "It's really about finding a niche over a period of time."

Schwer also said that the percentage of jobs associated with gaming and tourism has stayed flat in Clark County, meaning that diversification and job creation efforts outside the tourism industry have kept pace.

"The number of nongaming jobs have grown," he said.

Somer Hollingsworth, president of the Nevada Development Authority, had a similar take on the economic development efforts.

"When you look at gaming and the tremendous growth it has had and the fact that the diversified sector is keeping up, it's fantastic," he said. "It kind of puts in perspective what Southern Nevada is accomplishing."

He also pointed to the emergence of new companies, like technology supplier CDW Corp., which is building a North Las Vegas distribution center. San Diego-based technology giant Qualcomm Inc. also is building a North Las Vegas center. That site will serve as a hub for the development and distribution of entertainment content for mobile communication devices.

"When you look at those kinds of companies, you're opening the door a little bit and looking into the future," Hollingsworth said.

Kevin Rademacher covers utilities and finance for In Business Las Vegas and its sister publication, the Las Vegas Sun. He can be reached at (702) 259-4069 or by e-mail at kevinr@lasvegassun.com.