Beyond three score years and ten: prospects for longevity in Australia.

Most estimates and projections of life expectancy are based on period measures. This paper presents forecasts of cohort life expectancy for older generations derived using the Lee-Carter method of forecasting mortality. These cohort measures point to more years of life expectancy than the commonly-cited current period measures. The new forecasts also indicate a more rapid increase in future life expectancy than official projections assume. Policy-makers and those planning retirement should take into account that Australians are likely to live longer than currently envisaged

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The average length of human life has roughly doubled over the last 200 years. Most of this increase took place over the last 100 years. In Australia, life expectancy at birth was 57 years in 1901-10 and increased to 80 years in 2000. During the early part of the 20th century, the greatest gains were due to reductions in mortality from infectious and parasitic diseases at young ages, while during the later part reduced mortality from chronic diseases at middle and older ages was the dominant factor. Life expectancy at age 50 increased from 25 years in 1950 to 32 years in 2000.

These unprecedented increases in human life expectancy have prompted researchers to address the issue of whether there is an upper limit to human longevity. (1) To date, there is no consensus on whether such a limit exists, what the limit might be and how soon it might be reached. (2) Certainly the increases show no signs of slowing down, (3) giving no indication that a limit might soon appear on the horizon.

For the individual, increasing longevity presents the prospect of many years of post-retirement leisure but also the possibility of spending quite lengthy periods in various states of disability and ill-health. Thus, planning for retirement and old age--both lifestyle and financial--is becoming of increasing importance. Available evidence suggests, however, that people do not plan for a lengthy retirement. (4) Moreover, studies of the assets of older Australians show that many individuals (in particular, women and those living in high-cost centres such as Sydney) are woefully ill-prepared. (5) Further, many middle-aged Australians are grappling with issues of care of elderly parents, who are living beyond popular expectation, at a time when they are also planning for their own old age. Despite the backdrop of ever-increasing years of life, for many individuals, it is as though longevity has crept up on them without warning. Indeed, many elderly people are asking in tones of weary impatience, 'How long will life go on?'

What then are the longevity prospects of people living in Australia today? In particular what are the longevity prospects of today's population aged 50 years or older--those who are planning for retirement, facing retirement or experiencing old age? This paper examines this question using probabilistic forecasting methods. It concentrates on four population cohorts defined by their age in 2001: those aged 50 (labelled baby boomers), those aged 65 (labelled current retirees), those aged 85 (labelled current old-old) and those aged 90 (labelled current oldest-old). (6) The sex- and age-specific mortality rates for these cohorts are forecast over the remainder of their lives, and there rates are used to derive cohort life expectancies. The paper demonstrates the extent to which longevity is likely to increase over the lifetime of cohorts now alive. The uncertainty in the forecasts is discussed and comparison is made with the limited information on cohort mortality available in official publications. The implications at the individual level of these forecasts of increasing longevity are discussed in relation to the baby boom and older cohorts.

COHORT VERSUS PERIOD MEASURES