How important is economic growth? Does it really make people better off in the long run? Or, as the question is sometimes misleadingly put, “Can money buy happiness?”
a) Why is that last question misleading?

Answer:
Economic growth is the increase of real GDP (gross domestic product) in a given year, i.e. the rise in the country’s production of services and goods, adjusted with inflation rate. It means that economic growth reflects how well the county’s citizens improve their well being and standard of living. Economic growth is important because it builds the basis for the country’s citizens' future and ensures that societies move in a productive direction. It enables development in all areas of business, science and society, and advance in all areas of life. It is supposed to mean more comfortable and secure life and better public situation.
But it does not always have to be that simple. The countries which are traditionally supposed to be wealthy countries and whose citizens are well-off, may have very low (even below 1%), 0% or even negative economic growth (like in the eurozone in 2012 where the economic growth is -0.3% in 2012). On the other hand, there may be countries which enjoy high economic growth and in spite of this, their citizens live in poverty – like Brazil after World War II where in spite of 16% economic growth people lived in poverty.
Therefore economic growth itself does not make people better off in the long perspective. What really matters and what really shows whether individual people benefit more from the country’s economy, is the GDP per capita, showing the GDP for an individual citizen.
Can money buy happiness? It is a difficult question, because it is difficult to buy something that is not quantifiable. There is a cliché saying that money cannot buy happiness, but in my opinion an economist would look at the data of GDP per