Hundreds of thousands of people have left Russia over the last two years, citing a variety of political, economic, and personal reasons.
According to Russian government statistics, 203,000 people left the country permanently in the first eight months of 2014.
That was up from 186,000 in 2013, and experts predict the figure for 2014 will break Russia's one-year brain-drain record of 215,000 set in 1999.
Economist Konstantin Sonin is the latest prominent Russian to decide to leave.
Here are some of the well-known Russians who have left since Vladimir Putin began his third term as president in May 2012:
Konstantin Sonin, economist. A prominent liberal economist and commentator, Sonin announced on May 20 that he was leaving Russia to take up a teaching post at the University of Chicago. He said in a blog post that his decision was "linked to the political events of recent years." Sonin was reportedly forced out of his job at Moscow's prestigious Higher School of Economics earlier this year. In recent months, he had openly criticized the Kremlin over Russia's economic crisis and called for the sacking of corrupt government officials.
Yevgenia Chirikova, environmental activist. Chirikova moved to Estonia with her family in April. She said she left Russia for fear her children would be taken away from her. Chirikova is best known for her crusade against the construction of a highway linking Moscow to St. Petersburg whose route goes through the Khimki forest on the outskirts of the Russian capital. She has denounced corruption in the entourage of President Vladimir Putin and criticized Russia's actions in Ukraine.
Rustem Adagamov, photographer and blogger. Adagamov emigrated to the Czech capital, Prague, in March 2014 after Russian authorities investigated him on accusations of statutory rape -- accusations that he denies.
Sergei Guriyev, economist and former rector of Moscow's New School of Economics. He left Russia on vacation in May 2013 and decided not to return after being contacted repeatedly by prosecutors investigating possible new criminal charges against former oligarch Mikhail Khodorkovsky. "I left Russia for personal reasons," he wrote in The New York Times. "I personally prefer to stay free." Guriyev lives in France.
Oleg Kashin, journalist and blogger. Kashin immigrated to Switzerland in May 2013. He had been savagely beaten in 2010 in an attack widely believed to be retribution for his reporting and said that he feared persecution for his opposition political activity. He had reported about the road construction in Khimki Forest, at least two of whose opponents were also severely beaten.
Garry Kasparov, former world chess champion and Russian opposition political activist. He left Russia in June 2013, saying that he has not emigrated, but that he will not return to Russia until he feels he can do so safely. "Russia is and will always be my country," he wrote at the time. Kasparov lives in the United States.
Masha Gessen, writer, journalist, activist, and former director of RFE/RL's Russian Service. In December 2013, Gessen -- who holds dual U.S.-Russian citizenship and has lived in both countries -- announced that she was returning to the United States because of statements from some Russian officials calling for children to be taken away from gay parents. "Once they started talking about removing children from families," she told CBC television, "I felt like no risk was small enough to be acceptable. So we just had to get out."
Mikhail Khodorkovsky, former oil tycoon. Once the richest man in Russia, he spent 10 years in prison on embezzlement, fraud, tax-evasion, and money-laundering charges he says were politically motivated. Khodorkovsky was granted a presidential pardon and released in December 2013. He was immediately flown out of Russia. He has since lived in Switzerland, where he has been granted residency. He said in March that if he returned to Putin's Russia, "I'd end up back in a prison cell."
Pavel Durov, entrepreneur and founder of the social media site VKontakte. In early 2014, amid a ferocious business dispute at VKontakte, Durov left Russia. In April 2014, he announced he had been granted citizenship by the Caribbean nation of St. Kitts and Nevis. He says that VKontakte is now controlled by Putin insider Igor Sechin and Kremlin-friendly oligarch Alisher Usmanov.
Galina Timchenko, journalist and former editor of Lenta.ru. After the owners of Lenta.ru fired Timchenko in March 2014 over its coverage of the conflict in Ukraine, almost the entire staff of the site quit. In April, Timchenko and her team announced a new media project called Meduza, based in Riga, Latvia. She told The Daily Beast in November 2014 that she feels safe from Russian government pressure now. "I don't believe, not for a single second, that the Kremlin is able to throw their little cages over the huge Russian Internet," she said.
Leonid Bershidsky, journalist and founding editor of the Vedomosti daily. Bershidsky announced he was leaving Russia for Germany in June 2014, citing the conflict in Ukraine. "I have no desire to stay in Russia and pay a single kopek for Crimea," he wrote, referring to the Ukrainian peninsula that Russia took over in March 2014. "Stolen goods are stolen goods."
Marat Gelman, art curator and political consultant. Gelman announced in January 2015 that he was leaving Russia with the intention of setting up an art gallery in Montenegro. He ran into trouble in 2013 when he curated a show at the Perm Museum of Contemporary Art that ridiculed the 2014 Sochi Winter Olympics and Soviet dictator Josef Stalin.