You can tell a lot about a nation from its census - not only from the answers but also from the questions.

In the next census, for the first time, the Bureau of Statistics wants to ask about our second houses, and even our third ones.

''In the old days we all probably had a single house we lived in,'' census data director Jenny Telford said. ''But now many people have many places they call home? Children live in two houses in shared custody, workers fly in and fly out, many of us have holiday homes.''

The bureau has begun a period of consultation over how to word the question that will last until May.

In 2016, it also wants to ask how we earn our money. Ever since 1911, the census has merely wanted to know how much we earned, on the safe assumption we made it from work. But these days people are increasingly earning money from investments and many live on government benefits. The bureau hopes a new question asking how we get our income will give it a handle on what type of people are beneficiaries and what type are investors.

The bureau also wants to ask the questions a society asks when it gets old: who has long-term health problems and where do they live.

The bureau will also dispense with the army of 43,000 census collectors, posting letters with log-in details instead. Peter Martin