But several years ago, Yang quit many of these organizations to focus his attention on his newly established Foundation for China, which his wife described as more research-based than political.

“China sees this organization as radically anti-government, but it’s not,” Fu said.

Chinese authorities questioned Yang’s friends and co-workers about his activities when these acquaintances visited China, she said.

At the same time that he ran the Foundation, Yang was also working towards a doctorate, studying mathematical approaches to politics with Ramsey Professor of Political Economy Richard J. Zeckhauser ’62.

Zeckhauser called Yang an outstanding student with a “sparkling” personality.

“He was doing so much [with the Foundation] at the same time as he was doing this interesting research,” Zeckhauser said. “It was amazing.”

Fu said she tried to convince her husband not to return to China, arguing that it was too dangerous.

“He said that he would be quiet, and that no one would know who he was,” Fu said. Through the Foundation, Yang was studying changes in China’s political climate, Fu said, and just wanted to see these changes “on the ground.”

For over a week, Yang toured cities in northeast China and called Fu daily to check-in.

“He told me that if he didn’t call for 48 hours, it meant he was in trouble,” Fu said.

On April 26, Fu received an anonymous call saying that her husband he been detained.

For her part, when Fu tried to enter the country on Wednesday, she was stopped by Chinese immigration officials who said she posed a threat to the country. She was sent back to the U.S. via Vancouver and arrived in Boston late Wednesday.

—Staff writer David H. Gellis can be reached at gellis@fas.harvard.edu.