_LIES, DAMNED LIES AND POPULATION PROJECTIONS

LIES, DAMNED LIES AND POPULATION PROJECTIONS

The 19^th century British Prime Minister, Benjamin Disraeli, is generally attributed with the famous quote – “there are three kinds of lies: lies, damned lies and statistics.”  Perhaps he could have also included population projections.

The latest population forecasts for Victoria have been released by the State Government and there are some interesting projections.

Victoria in Future 2014 (VIF 2014) represents the latest and most comprehensive population modeling for the State.  It incorporates the latest ABS data supplemented with land supply and other information to reflect local circumstances.

Figure 1 Components of Population Change Victoria 2011 to 2051 Source: VIF 2014

The Australian Bureau of statistics (ABS) released its population projections in November 2013.  The ABS figures showed that Victoria was growing faster than previously anticipated.

The VIF 2014 projections suggest that Victoria’s population is expected to grow even faster than the ABS predicted in November 2013.  The VIF 2014 figures show:

• overseas migration will be the largest contributor to Victoria’s growth, accounting for 60 per cent of the State’s growth between 2011 and 2051;
• most of the remaining 40 per cent is due to natural increase – that is, births minus deaths;
• increasing levels of migration out of Greater Melbourne, leading to higher projected population for Victoria’s regions than the ABS forecasts.

The current population for Greater Melbourne, Victoria’s regions and Victoria as a whole are estimated as follows.

A summary of the projections in 2051 for Greater Melbourne, Victoria’s regions and Victoria as a whole is presented below.

Figure 2. Annual population change by component Victoria 1981 to 2051 Source: VIF 2014

Over the next 20 years, population growth in the metropolitan Melbourne region (defined slightly differently from ‘Greater Melbourne’) is projected to occur in the sub-regions as follows:

• northern (an additional 450,000 people);
• southern (450,000);
• western (420,000);
• central (270,000);
• eastern (180,000).

VIF 2014 population projections show strong growth for Victoria’s 10 regional cities.  By 2031, more than 54 per cent of people who live outside Greater Melbourne will reside in one of these regional cities.  Regional city growth accounts for more than 60 per cent of the population growth in Victoria’s regions over the next 20 years.  The highest population growth in this period is projected to be in Greater Geelong (73,000 people), followed by Ballarat (47,000) and Greater Bendigo (44,000).

So what does all this mean?

First, one should always remember that projections are only as good as the assumptions that feed into the model.  A change to any of the variables (overseas migration, interstate migration, births, deaths and so on) will have an impact on the VIF 2014 projections.

Second, State Governments of all types have historically had a poor record when it comes to forecasting population growth.  Projections have invariably been way too conservative or optimistic in many of the milestone planning strategies throughout the last 50 years.  Despite more sophisticated models and extensive experience, the task of forecasting future population figures is extremely difficult.

Third, we should heed the advice of Prime Minister Disraeli.