Despite great medical advances that have lengthened human life spans, your chances of living a very long life may be lower than you’d hoped. That’s the conclusion of a study by two longevity experts who reviewed the standard models that predict mortality rates and turned up a major error. Instead of confirming that death rates drop once people reach their 80s or 90s – as experts have assumed for many decades — results showed that the risk of dying continues to increase each year, no matter how old people are.