All those who follow the fate of the New England Patriots know well what the term “rapidly diminishing window of opportunity” means. It means that the organization better focus on assembling the best possible teammates for Tom Brady in the next two or three years, or their chances for another championship are likely to disappear into a distant and foggy future.

Much the same thing can be said of the Maine economy – with one major exception. Instead of depending on a single superstar player and gradually extending the twilight of his long and brilliant career, we are depending on a single and – at least in its own view – superstar generation and extending the twilight of its long run of dominance.

Over the 10-year period from 2001 to 2010, the number of civilian, non-institutional (meaning not in the military or living in an institution) Mainers aged 65-plus averaged 186,000, ranging from a low of 171,000 in 2001 to a high of 196,000 in 2009.

The labor force participation rate of this cohort – meaning the percentage of the group either employed or looking for work – averaged 14.8 percent, ranging from a low of 12 percent in 2002 to a high of 17.2 percent in 2010.

In 2011, the first of the baby boomers (those born in 1946) turned 65. In that year, the 65-plus age cohort in the population jumped to 205,000, and its participation in the labor force jumped to 20.6 percent. In each of the following four years, the size of this 65-plus age cohort increased, reaching 250,000 in 2015. And its participation rate increased as well, reaching 21.3 percent in 2015.

The reasons for this increased participation rate are many:

• The Great Recession and the consequent need of many over age 65 to continue to work to support themselves.

• The replacement of many defined-benefit retirement programs, funded by employers, with voluntary-contribution 401(k) plans, funded by employees and employers who choose to participate.

• The boomer heritage of greater female participation in the workplace, leading many women to choose to continue their careers after age 65.

Over this same period of post-2011 generational passage, there has been an opposite trend at the other end of the age spectrum.

Maine’s civilian, non-institutional population age 16 to 34 declined from 300,000 in 2011 to 273,000 in 2015. And, in what is both a troubling and perplexing trend, the labor force participation rate of this younger age cohort fell from 72.3 percent in 2011 to 70 percent in 2015.

In the 16-to-24 age cohort, this trend has been even more pronounced, with the total number dropping from 159,000 in 2011 to 133,000 in 2015 and their labor force participation rate dropping from 63.5 percent to 60.2 percent over the same period.

Again, the reasons for these trends are numerous:

• Overall slow employment growth.

• The migration of Maine’s “best and brightest” to out-of-state opportunities.

• The inadequate education and training of those young Mainers who do not emigrate.

• The choice to remain in school rather than seek a job.

But regardless of the reasons, the combination of these trends – increased labor force participation rates among older workers and decreased participation rates among younger workers – cannot continue indefinitely without dangerous consequences. Our window of opportunity for a relatively smooth transition to economic sustainability is shrinking rapidly.

Baby boomers, whatever their sense of immortality may be, cannot work forever. And millennials – or whatever moniker we choose to hang on our younger generation – cannot and probably do not want to continue the historically low rates of labor force participation that have been evident over the past few years in Maine.

Maine’s window of opportunity for achieving balanced economic prosperity depends on finding new and far more effective ways of engaging our young people – both those now in Maine and those we might attract to Maine – in the career paths that both we and they so desperately need.

Charles Lawton is chief economist for Planning Decisions, Inc. He can be contacted at:

clawton@planningdecisions.com