The simple answer is, it depends. 

One factor to consider is the purpose of the blog. 

Is it to communicate with:

• Staff
• Partners 
• Prospects 
• Clients 
• Shareholders

If you are a public company CEO, you need to be very diligent as to what you write. You cannot comment on things that may move the stock.

Is it to build your personal brand? 

Most public company CEO's stick to some area of expertise like Jim Estill of New Horizons. With respect to Jim's blog, he focuses on leadership and has quite a following. He is highly respected because he delivers value to his readership. This value word is key in social media. 

It can be challenging for him to blog about happenings at Nu Horizons all the time, because there may not be items of interest for his audience. Jim has chosen the personal brand route and that works for him. 

Other considerations for blogging are time and desire 

Many CEO's don't want or need one more thing on their to do list. They need to see the value of blogging in order to deliver value. So, trying to convince all CEO's to blog is an uphill battle

even after outlining all the clear benefits of:

• Brand building of the corporation 
• Personal Brand building of the CEO
• Effective employee communication 
• Positive effect on organic search for the corporate web site
• Free Public Relations
• Low Cost
• Direct communications with stakeholders
• Differentiate from your competition

Those CEO's that are ready to blog, will. Some may use ghost writers which is OK as long as the content reflects their views. Authenticity is critical in social media and you always hope that what you are reading is the real deal.Todays world of blogging serves many purposes, but it starts with a clear vision as to why you are blogging and to whom.