What is the book you have given most as a gift, and why?

Ever since adolescence, [my elder sister Anna] has been an enthusiastic admirer of the great Swedish writer, the Nobel Laureate Selma Lagerlöf, and she infected me so much with her enthusiasm that I decided to become a writer and describe Italian saga "à la Lagerlöf". But things were to take a different turn.

It was not long after Kenneth Arrow's path-breaking study of social choice, Social Choice and Individual Values, was published in New York in 1951, that my brilliant co-student Sukhamoy Chakravarty drew my attention to the book and to Arrow's stunning "impossibility theorem" (this must have been in the early months of 1952). Sukhamoy too was broadly attracted by the left, but also worried about political authoritarianism, and we discussed the implications of Arrow's demonstration that no non-dictatorial social choice mechanism may yield consistent social decisions.

A book also pushed me to become a medical doctor. I was deeply inspired by Torao Tokuda, a physician who founded a hospital group in the 1970s that tried to revolutionize the Japanese medical care system.

In Ge Hong's A Handbook of Prescriptions for Emergencies (肘后备急方), I noticed one sentence "A handful of Qinghao immersed in two liters of water, wring out the juice and drink it all" (青蒿一握, 以水二升渍, 绞取汁, 尽服之) when Qinghao was mentioned for alleviating malaria fevers. Most herbs were typically boiled in water and made into a decoction before taken by the patients. This unique way of using Qinghao gave me the idea that heating during extraction might have destroyed the active components and the high temperature might need to be avoided in order to preserve the herb's activity.

When I was 16 years old, I read the book from Hans Selye. Hans Selye is a Canadian scientist, but he was Hungarian so his book was translated to Hungarian. His mantra was that you have to focus on things that you can change. Many young ones are giving up because they can see that their friends or their colleagues are advancing, and it seems that they do less and somehow, they get higher salary and promoted. I told that if you notice that then you already took away your attention what you can change. Because you cannot change that.