Winston Churchill (Left) and Warren Buffet (Right) Churchill: Carl Mydans—The Life Picture Collection/Getty Images; Buffett: Lucas Jackson—Reuters

The results of the 2015 Fortune 500 CEO survey are in…

Updated: Jun 04, 2015 12:43 PM UTC

What are your company’s biggest challenges?*

1. The rapid pace of technological innovation 72%
2. Cyber security 66%
3. Increased regulation 61%
4. Shortage of skilled labor 34%
5. Management diversity 25%
6. Competition from a start-up 20%
7. Shareholder activism 20%
8. Competition from China/developing countries 4%

*Percent who answered either “single biggest challenge” or “one of our top three or four challenges."

Who is your company’s most dangerous competitor?

1. Another Fortune 500 company 57%
2. A smaller established company 24%
3. An overseas competitor 16%
4. A recent startup 2%

Winston Churchill (Left) and Warren Buffet (Right)Churchill: Carl Mydans\u2014The Life Picture Collection\/Getty Images; Buffett: Lucas Jackson\u2014Reuters

CEOs on Leadership

•  94% of respondents agree with the statement “My company will change more in the next five years than it has in the last five years.”

•  84% agree with the statement “It would be easier to manage my company if it were a private company.

•  67% say a public company has equal responsibility to customers, shareholders, employees, and the broader community.

•  51% think it’s important to take a stand on some public issues.

•  82% plan to employ more people two years from now.

•  75% of CEOs believe CEOs are paid appropriately.

•  76% of respondents think society will benefit “if employees take responsibility for their own health care and retirement.”

•  80% of CEOs say they directly answer all or most of their email.

•  The average CEO has between four and 12 direct reports.

•  More than 60% of respondents believe that optimal tenure atop a Fortune 500 company is five to 10 years.

Courtesy of Harper Collins Publishers

Favorite Books of CEOs

Favorite book: Good to Great by Jim Collins
Runner up: Outliers by Malcolm Gladwell

Ullstein Bild\u2014Getty Images

Leader most respected by CEOs

Winner: Ronald Reagan
Runners up: Winston Churchill and Warren Buffett (tie)

Tim Cook (Left) and Jamie DimonCook: Stephen Lam\/Getty Images; Dimon: Gary Cameron\u2014Reuters

Most Admired CEOs (excluding themselves)

Winners: Tim Cook and Jamie Dimon (tie)

A shorter version of this article appears in the June 15, 2015 issue of Fortune with the headline 'Fortune 500 CEO Survey.'