American scientists from Princeton University found out how much money one needs to be happy. The ideal sum is $75 thousand dollars a year or 6250 dollars a month (190 thousand rubles). Economist Angus Deaton & psychologist Daniel Caneman who made the research note that precisely this sum of money can be seen as a kind of border line. If a person gains less he or she suffers more from different problems. At the same time it doesn’t mean that the level of happiness continues growing with more than $75 thousands a year. They found out that more money doesn’t add more happiness. As for Russia one forth of its citizens evaluated happiness for 100 thousand rubles a month, recruiting website Superjob.ru reports. Another 25% of Russian citizens claimed 55-99 thousand rubles would be enough, while 16% think they need 100-149 thousands a month to be happy.