Recently,CCTV journalists have approached pedestrians with their cameras,held a    microphone to their mouth and asked a simple question :"Are you happy?" The question has caught many interviewees off guard.Even Mo Yan who recently won a    Nobel Prize,responded by saying:"I don't know". While the question has become a buzz phrase and the Internet plays host to heated    discussions,we ask:What exactly is happiness ?And how do you measure it? In the 1776 US Declaration of Independence,Thomas Jefferson set in writing the people's unalienable right to"Life,Liberty and the pursuit of Happiness".Last year,235 years on,China's Premier Wen Jiabao told the nation:"Everything we do is aimed at letting people live more happily."At last year's National People's Congress,officials agreed that increasing happiness would be a top target for the 12thfive-year plan. US psychologist Ed Diener, author of Happiness:Unlocking the Mysteries of Psychological Wealth describes happiness as "a combination of life satisfaction and having more positive than negative emotions",according to US broadcasting network PBS.This may sound straight forward enough,but it still doesn't explain what determines people's happiness. Many argue that happiness is _ and that there is no single source.It also means different things to different people.For some,happiness can be as simple as having enough cash. Researchers believe happiness can be separated into two types:daily experiences of    hedonic well-being;and evaluative well-being, the way people think about their lives as a whole.The former refers to the quality of living,whereas the latter is about overall happiness,including life gods and achievement.Happiness can cross both dimensions. Li Jun,a psychologist and mental therapy practitioner at a Beijing clinic,says:"Happiness    can mean both the most basic human satisfaction or the highest level of spiritual pursuit. It' s a simple yet profound topic ." Chen Shangyuan,21,a junior English major at Nanjing University of Aeronautics and Astronautics,said his idea of happiness always evolves."At present it relates to how productive I am in a day,"he said."It might be linked to job security or leisure time after I graduate." Then there is the question of measuring happiness.Does it depend on how many friends we have,or whether we own the latest smart phone? Is it even quantifiable? Economists are trying to measure happiness in people's lives.Since 1972,Bhutan's GDP    measurement has been,replaced by a Gross National Happiness index.It is calculated according to the peoples'sense of being well-governed,their relationship with the environment,their    satisfaction with economic development,and their sense of national belonging. In 2009,US economist Joseph Stiglitz proposed "to shift emphasis from measuring economic  production to measuring people's well-being".But is well-being more easily measured? From what Thomas Jefferson and Wen Jiabao mentioned in the passage,we know  _  .
people's happiness is determined by great people people's happiness is an important target for the development of a country people in all countries have the right to ask the government for a happy life People both in China and America are living a happy life