Here, e.g. is one such call: In Solidarity with People Affected by the ‘Muslim Ban’: Call for an Academic Boycott of International Conferences held in the US
"Among those affected by the Order are academics and students who are unable to participate in conferences and the free communication of ideas. We the undersigned take action in solidarity with those affected by Trump’s Executive Order by pledging not to attend international conferences in the US while the ban persists. We question the intellectual integrity of these spaces and the dialogues they are designed to encourage while Muslim colleagues are explicitly excluded from them."
I have had an opportunity to think about this regarding the ASSA conference run in January by the American Economic Association, and it seems to me that such a boycott won't help the majority of academics (students and professors) from the banned countries who come to our conference, or to many American academic conferences.
In our (the AEA's) particular situation, my sense is that we have had few if any Yemeni and Sudanese economists participating in the AEA meetings, and the people potentially affected by the current U.S. entry bans are mostly Iranian.* And the majority of Iranians who have participated seem to be working or studying in the U.S.
So…if a travel ban is in place next January, and we moved the conference to some civilized city like Toronto, we would be depriving most of the potential Iranian participants of the ability to attend, since they couldn’t leave and then reliably re-enter the U.S..
My current sense is that the AEA will decide to take care of the Iranians as best we can (which for the minority who aren’t in the U.S. may involve some electronic communication efforts), rather than cater to any economists whose scruples would require us to abandon the Iranians living and working in the U.S. by moving the conference elsewhere.
To be clear, I think moving the AEA meetings outside of the U.S. would harm the majority of Iranians who participated in past years.
Of course I’m hopeful that we’ll have come to our senses long before then.
*see this article in the Chronicle for a wider view of who studies in the U.S.:
Why the Travel Ban Probably Hits Iranian Professors and Students the Hardest
see also the data compiled by the Institute of International Education:
International Students: All Places of Origin 2014/15 - 2015/16, and for previous years: 2016 | 2015 | 2014 | 2013 | 2012 | 2011 | 2010 | 2009 | 2008 | 2007 | 2006 | 2005 | 2004 | 2003 | 2002
Selected Years 1950-2000
Universities Spoke Up in Case That Led to Ruling Halting Trump’s Travel Ban