It's disheartening to learn that the number of youngsters aged 16 and under who are working in a Saturday job has fallen by more than a fifth since 2012.

In some cases, this is because the jobs no longer exist: demand for youngsters to deliver newspapers and magazines, for instance, has fallen sharply over the past decade, but the reason most frequently cited to explain the decline is school work.

It's disheartening to learn that the number of youngsters aged 16 and under who are working in a Saturday job has fallen by more than a fifth since 2012. In some cases, this is because the jobs no longer exist: demand for youngsters to deliver newspapers and magazines, for instance, has fallen sharply over the past decade, but the reason most frequently cited to explain the decline is school work.

In what a cynic might suggest is an explanation lifted straight from the 'dog ate my homework' book of excuses, thousands of young people say they're too busy revising to get a part-time job.

This is disappointing. Not because we want a return to children up chimneys, far from it, but because not working as a teenager can have a detrimental impact upon future employment opportunities. A Government report, submitted in 2015, found that those who hadn't worked as teenagers were 'ill-prepared for full-time employment'.

That's hardly a surprise, and it's wrong to tar everyone with the same brush, but, over the years, various studies have highlighted the benefits to teens of holding down a part-time job.

Some are obvious. Being a teenager can be expensive and many families cannot afford the 'essential' trappings of teen life: phone, driving lessons and those 'incidental expenses' which cover a multitude of outgoings. The teenager who can spend money she earns herself, however, is unlikely to receive much parental flak for shelling out on 'essential' purchases.

Another enormous benefit is the experience even the most menial job gives our working teenager. Job markets increasingly favour those with experience over education and although a degree is still extremely valuable, its value is enhanced when combined with a well-written CV that shows blocks of work experience.

Furthermore, teenagers who work part-time are effectively demonstrating, either to a future employer or university admissions officer, that they're responsible and can successfully balance work and their studies.

Research conducted in the US has shown that teenagers who work part-time during the school year tend to earn higher exam grades than those who don't work. This apparent anomaly is attributed to working youngsters having a limited amount of time to get their school work completed, a factor which encourages them to get it done.

Of course, working in any capacity builds confidence and self-reliance which helps teenagers feel – and become – more independent: no bad thing if they're planning to go to uni. Yet perhaps the most important benefit that accrues from working part-time as a teenager is habit. The habit to save.

David Attenborough could probably have a field day investigating why it happens, but the simple fact is that youngsters who work tend to become natural savers in later life and, as a consequence, save more as they get older, becoming steadily richer than many of their peers who didn't have a part-time job.

Embracing the need to save before you spend is as good a rule for financial success as any, but in a world where everything is available on credit, it can be highly difficult to adhere to.

Remarkably, however, the 'save before you spend' mantra is sown most effectively during our teenage years. Having money for the first time does this to people. They're no longer completely reliant on parents and, if they wish, can save to buy things their folks might consider luxuries. Saving to acquire a specific target, from cosmetics to cars or a house, is best achieved if the savings habit is learned at an early age.

Granted, it can be supplemented in various ways: by avoiding buying items you don't really need; saving a specific percentage of your income (15% is a common target), or not carrying lots of cash (or credit cards) around as it becomes far too easy to engage in that poverty-inducing exercise, the impulse purchase.

A growing number of online banks and 'robo-advisers' targeted specifically at the millennial demographic allow you to 'round-up' your change when buying a coffee, book, etc and deposit it into your account. It is quite amazing how 25p here and 50p there mounts up.

Teenagers are not bothered about pensions or mortgages. They have plenty of time for those. But one of life's ineffable facts is that the sooner you have your own income, however modest, the sooner you will acquire the saving habit: an enormously valuable asset that can set you on a course for lifelong wealth and security.