As large populations of older people move past their peak spending years in some of the most lucrative markets in the world, demand will shrink dramatically for all kinds of products that are predominantly purchased by younger age groups. For most companies selling consumer products and services, that’s bad news – unless they take steps now to head off this grim demographic destiny.

In the U.S., Europe, and Japan aging populations are being followed by generations too small in numbers to make up for the inevitable drop in consumer spending that will occur. Confronted with this demographic and economic shift – the greatest in modern history – consumer-facing businesses will have to do three things supremely well.

First, they will need to develop some essential long-term strategies. These include relentless cost-cutting, readiness to acquire weaker competitors when they falter, willingness to shed non-core businesses, and focus products that meet the needs of aging populations.

Second, they will also need to leverage core assets in emerging markets. Conventional wisdom says that means the BRIC countries – Brazil, Russia, India, and China. That is a little over half right. Brazil and India certainly look promising, but China is attractive only for the next ten years. Then it begins a slow decline, in part due to its one-child policy from the 1980s onward. Russia looks least promising of all, with 21 percent of its population to be 65 or older by 2030, versus 13 percent today. More promising demographic trends may be found in Malaysia, Indonesia, Vietnam, Turkey, Thailand, and the Philippines, among other places.

Third, and perhaps most important of all, consumer-facing companies will need to find leaders who have the requisite skills and experience to execute those strategies, including superior competencies in operational excellence, strategic discipline, portfolio management, and multi-market knowledge and sensitivity.

How big can the differences in spending be between the generations? In 2009 in the U.S, for example, people age 25-34 spent an average of $229 on cereal and cereal products; the much larger cohort of people 65 and older averaged only $150. Similarly, 35-44 year-olds spent an average of $401 on non-alcoholic beverages and $515 on alcoholic beverages while the over 65 cohort averaged $262 and $300 on those categories, respectively. Consumer facing companies will also feel the pinch as retailing contracts – mall vacancies are at their highest level in 11 years.

Demographics may be destiny but consumer-facing companies that can embark on the right strategy, find the right talent to execute it, and do it right now in the right markets, will control their own destinies.

For a more detailed look at these issues, read Boomers to Bust, the coming demographic headwind for consumer-facing businesses.