Any research about “few markets” that expect external links to be opened in new windows/tabs?

Question

Google AdSense, an advertisement service, documents in "Opening the ads in a new window":

Generally, it is our policy to not allow Google ads to open in a new window. However, in a few markets, including China, we've found that opening ads in a new window better aligns with expected internet behavior and provides a more consistent, intuitive user experience.

Is there any published research about the culture/country difference regarding opening links in new windows/tabs?

Should we really open external links in new windows/tabs by default for users from these "few markets"? Do these users expect all external links to be opened in new windows/tabs or would an icon/notice still be advisable?

I couldn’t find anything mentioned in the questions:

• Is there ever a good reason to force opening a new browser window?
• Opening website external links in new window -- published usability tests
• When (if ever) should links be opened in a new window?

Answer 1

I couldn't find any research, so I have conducted my own. I've looked at the top 5 websites in China and in the United States, according to Alexa.

For the top websites in China:

Site        | # Links | # New Window | % New Window
baidu.com   | 26      | 3            | 11.5%
qq.com      | 1026    | 985          | 96.0%
taobao.com  | 398     | 335          | 84.2%
sina.com.cn | 2047    | 1849         | 90.3%
hao123.com  | 810     | 791          | 97.7%
              4307      3963           92.0%

So about 92% of all links on Chinese websites open in a new window.

For the United States:

Site          | # Links | # New Window | % New Window
google.com    | 48      | 4            | 8.3%
youtube.com   | 329     | 5            | 1.5%
yahoo.com     | 211     | 6            | 2.8%
amazon.com    | 308     | 1            | 0.3%
wikipedia.org | 313     | 0            | 0.0%
                1209      16             1.3%

So about 1.3% of all links on United States websites open in a new window.

So it is obvious that there are two different sets of expectations amongst these groups of users, and opening in a new window might well be the expected behaviour for Chinese users.