Studies have also found that getting low amounts of sleep regularly creates a progressively negative change in performance over time.

Researchers found that, ­during the first week of sleep deprivation, test speed only slowed by about a second; however, by the third week, it had slowed by twice that amount.

When people are sleep ­deprived, they are more prone to moodiness in the workplace and this can lead to poor work relationships, which can then affect the entire organisation.

Adults are not the only ones suffering from a lack of sleep in Hong Kong; it also affects schoolchildren.

In an effort to ensure they do well in exams and because of tests such as the Territory-wide System Assessment, many ­parents have their children attend a lot of tutorial classes and extracurricular activities.

Therefore, it is no wonder that children as young as Primary Three are not getting the eight hours of sleep a night that they need. This is very obvious in classrooms, where so many ­pupils doze off.

A study conducted in 2013 showed that a lack of sleep in teenagers caused “brain deterioration” in the long term.

When children do not get enough sleep at night, their brains are not as sharp the next day, at least in the area of ­abstract thinking and creativity.

It is time that we took a ­serious look at this issue.

Eunice Li Dan-Yue, Singapore

Get message across about plagiarism

I refer to the letter by Chloe Hung Yee-ching (“Why some students resort to plagiarism”, February 22).

Many students in Hong Kong plagiarise from online ­resources or copy the work of their peers.

The main reason for this is that they are given far too many assignments and tests, and ­neglect their homework.

I was once that kind of ­student, believing that homework was a waste of time and I could learn everything I needed in class.

However, I gradually came to recognise that homework, ­including assignments, is ­important.

These assignments enable students to apply the knowledge they have learned in class and help with revision. ­Doing an ­assignment gives them a more complete understanding of a subject.

Students who plagiarise do not get that full understanding.

Also, very few students can be described as very gifted. Most cannot just sail through their studies, but have to make a real effort and work hard. If they fail to really work at an assignment and resort to plagiarism, they will not learn much.

The best way to deal with the problem of plagiarism in Hong Kong schools is to teach ­students to appreciate the importance of working hard on their own when doing assignments.

However, some will continue to act in this dishonest way ­unless they are made to understand the consequences of their actions if they are found out.

Schools must make it clear to youngsters that if they are found guilty of plagiarism, they face heavy penalties and that they can only gain academically if they do their homework unaided.

Anson Sin, Tseung Kwan O

Disneyland should target local residents

Hong Kong Disneyland has ­reported a loss for the first time since 2011 (“Disneyland hit hard by slump in tourism”, February 16).

The opening of the Disneyland in Shanghai later this year is also likely to have an effect on the Hong Kong attraction and how many mainlanders go to it.

It may be time for the company to look at this loss and think about a change of tack. It should not just focus on attracting tourists, but do more to get locals to visit.

In the past, some local residents were reluctant to visit the theme park because there were so many mainland tourists and they also found the tickets too ­expensive With the present slump in visitor numbers, they might now be tempted to make the trip out to Lantau.

Disneyland should come up with more promotions which are tailored to the local market.

Wong Wing-yan, Yau Yat Chuen

Losses prove theme park must be closed

The report (“It’s a slow year after all: Hong Kong Disneyland ­reports first annual business loss since 2011”, February 15) caused a wry chuckle.

In my letter (“It makes sense to shut down Disneyland”, ­February 4), I argued that the Penny’s Bay plot be given over to housing on the basis that it was a busted flush.

With losses of HK$148 ­million, it really is time that we bit the bullet, swallowed our pride, and admitted that we made a complete hash of inviting Disney in to the city to set up an amusement park.

Let’s dismantle the attractions and turn the land over for the construction of affordable homes for the young, many of whom feel disenfranchised. If we do that, then much of the silliness that recently went on in Mong Kok will in future probably be averted.

Jason Ali, Lantau

Public housing target probably not realistic

In the policy address it was announced that over five years, to help deal with the housing shortage, 97,100 public housing units will be built,of which 76,700 will be public rental housing units and 20,400 subsidised sale flats.

However, no timetable has been laid out detailing when the building of these apartments will get under way.

Also, the administration must change its policy on land use as there is not enough available land to construct all the homes that are needed. It has to negotiate with developers for a change of land use and this wastes a lot of time. Therefore, I do not think the administration will be able to meet this target.

The chief executive missed a golden opportunity to correct long-standing issues regarding housing policy.

Pun Yi-tik, Kwun Tong

Massive spike in rents too much at market

I would like to voice my concern about the way wet markets are managed by The Link Management in housing estates.

For the past 20 years, I have been shopping happily in the market in Lung Hang Estate, Tai Wai.

The stall owners and housewives get on well and a good community spirit has ­developed. But, all of a sudden, The Link closed the stalls for renovation. We were shown videos about the renovation ­and were told there would be a great improvement to the shopping environment.

All shoppers will welcome that. But, when we talked with the stall owners, we learned that they would not be able to pay the post-revamp rents. For instance, a frozen food stall holder paying HK$20,000 per month will have to pay HK$80,000. The number of customers is unlikely to ­increase, so how can that vendor make ends meet?

Prompt action is ­needed by the government to ­resolve this matter.

E. Law, Sha Tin

Older urban areas can be transformed

I refer to the letter by Tong Tak-yu (“Revamp urban areas and save green-belt land”, February 22).

I agree that more urban areas can be used for housing rather than green-belt land. This can save more of our natural environment and precious habitats for our wildlife.

Also, urban areas that have been suitably redeveloped and are no longer run down can ­provide decent housing and a good environment for young people where they can mix with friends.

These urban areas are also more likely to have study rooms, a library and other facilities which can be used by youngsters.

It depresses me when I see the government failing to make good use of what is available. Many schools lie empty and nothing has been done to redevelop them. Officials must come up with a good town-planning strategy so that these older urban areas can be revamped.

Fok Pui-yi, Tseung Kwan O

Little in way of entertainment from RTHK

I do not think RTHK is ready to take over Asia Television’s ­licence in April.

RTHK does not make many programmes and those it does show lack variety; they’re mostly current affairs and documentaries. I doubt if it will produce many shows that come under the category of entertainment.

Viewers want to see dramas and other entertaining shows.

Au Yeung Kwong-fai, Tsuen Wan