The gettin’ old blues. The Byron Bay Blues Festival, held over the Easter long weekend, turned out to be an unexpectedly good spot to contemplate the Treasurer’s recent warning that the official retirement age could go to 70. Many blues musicians are touring at an age when most people are shutting up shop. Legendary guitarist Buddy Guy, 77, did a blistering 90-minute set, as did blues harpist James Cotton, who at 78 at least had an instrument he could play sitting down.

Although the media has been full of dire warnings about the health issues of working till 70, not everyone wants to retire. The number of people in the world over 65 is set to double in the next 25 years, and many of us do not intend to play bowls. The good news for Crikey readers, who seem to be as clever as they are enlightened, is that the more educated you are, the less likely you are to quit work.

According to a story published in this week’s Economist magazine, better-educated older people are far more likely to work past the usual retirement age of 55-65. Researcher Gary Burtless of the Brookings Institution has calculated that in the United States, only 32% of male High School graduates are in the workforce between 62 and 74. However, 65% of men with a professional degree are working after 62, while for women the figures are one-quarter and one-half, respectively.

There are good reasons for that, of course. Manual labourers may not want to work past a certain age — there are few 70-year-olds on building sites — and higher-skilled workers tend to be paid more, which is an incentive to keep working.

And although it’s thought that older workers are less effective, this isn’t always the case. At a time of ever-improving technology, the attributes that enhance productivity may have more to do with motivation, people skills and experience than cognitive speed. Recent studies suggest that older workers are, in fact, disproportionately more productive, probably because they are disproportionately better educated. German academics have shown that older workers who stayed in the labour force have tended to move into jobs that demanded more cognitive skill, earning them high salaries. This is good news for countries like Germany, which has a rapidly ageing populations due to low birth rates.

Although I can’t play an instrument, it is inspiring to go and see a few musicians, some of them not much younger than my parents, whipping up a crowd of 50,000 fans in the main tent at Byron. See you next year.

CTRL+Z for email. Most of us have at some point experienced email remorse — that slow realisation that sweeps over you, 10 minutes after pressing the send button, that you shouldn’t have counselled your boss on her poor management skills, or written “10 things I hate about your boyfriend” to a mate. Whether it’s that second glass of wine over lunch or hitting the keyboard after an argument, we’ve all sent something we regretted.

Up until now, other than the usual remedies of flowers and apologies, there hasn’t been much you could do about it. However, for users of a new email service called Pluto Mail, those problems could be in the past.

Created by two Harvard law school students, the free web-based email service enables users to recall emails and edit them anytime after they’ve been sent,  providing the email hasn’t been opened (the service will also notify you when the recipient has opened your email). Pluto users can configure their emails to expire, just like messages sent on Snapchat. Auto-expire can be set so emails expire three days after they are sent or five minutes after they have been opened. The idea is to recognise that not every email needs to be around forever, say creators David Gobaud and Lindsay Lin.

“When you have a conversation in real life, it doesn’t follow you for the rest of your life,” Gobaud said. “Sure, there are some business emails or emails related to a contract you might want to keep but most other emails, you want them to go away.”

One of the useful features of the service is that recipients do not need to use Pluto or install any software to read their emails. Instead, Pluto displays message content as an image, so it’s difficult to copy text to save elsewhere. “Pluto is for anyone who wants more control over their sent email or anyone concerned about privacy,” Gobaud said.

On the clock. Taiwanese-American artist Tehching Hsieh punched a time clock in his studio, every hour on the hour, 24 hours a day, for an entire year and then made an artwork about it, One Year Performance 1980-1981, which opens at Sydney’s Carriageworks this week and will be on show until July 6 …

The installation is made up of the documents he produced as he punched the clock, a poster and artist’s statement, a witness testimony, the artist’s uniform, the time clock, 366 time cards, 366 film strips comprised of the 8621 times he photographed himself punching the time clock, and a 16mm film condensing the gruelling year-long experience into six minutes.

Based in New York since 1974, Hsieh is internationally recognised as a leading practitioner of durational performance. In the late ’70s, he gave five separate one-year-long performances, including spending a year in solitary confinement without any communication; a year devoted to making the time clock piece; and a year spent living without any shelter on the streets of New York. Another year was spent being  tied closely to the artist Linda Montano without ever touching; the last one was a  year of total abstention from art activities and influences. In 1986 the artist announced he would spend the next 13 years making art but not showing it publicly.

If you ever wanted to see something that sums up the experience of suffering for art, go see One Year Performance 1980-1981.