A city that is active 24 hours a day extends the hours of a city’s economy, generating more jobs, activities and social solidarity. But there are downsides as well.

In a 2011 study of the world’s 24-hour cities, Cairo was ranked the “most 24-hour” of all. Just behind Egypt’s capital came Montevideo, Beirut, six Spanish cities (Malaga, Zaragoza, Madrid, Barcelona, Valencia and Seville) and Buenos Aires. London was ranked 17th, Paris 18th and New York 32nd.

Virtually no cities are entirely 24-hours all year round, noted Marion Roberts, a professor of urban design at London’s University of Westminster. Extending late-night hours extends the hours of a city’s economy, Roberts said, but there are downsides as well. “In the UK, Europe and Australia, a lot of their ‘24-hourness’ has been about extending entertainment – which has [disadvantages] for city centre dwellers unless carefully managed,” explained Roberts, who co-authored the 2009 book Planning the Night-time City. “However, it does generate more jobs, activities and social solidarities.”

Common concerns about keeping a city up all night relate to noise, traffic and alcohol consumption. In Washington DC, where city officials are debating the advantages of extending late-night hours, some politicians and residents oppose the idea as they think it will also lead to an increase in crime.

And the concerns are not misguided. For example, a 2010 World Health Organization study stated that New York is the world’s loudest city, followed by Tokyo, Nagasaki and Buenos Aires. In addition, the Institute of Alcohol Studies found that the late-night economic activity of 24-hour cities is largely tied to alcohol consumption, a conclusion Roberts arrived at in her own 2005 study on 24-hour cities, which said that this is “not a desirable urban philosophy for the 21st Century”. Interestingly, in the same 2005 study, “Conflicts of Liveability in the 24-hour City”, where Roberts and her colleague Chris Turner examined the nightlife of London’s Soho, police statistics did not report higher levels of crime, but noise and traffic levels were higher than in other parts of the city.

“The key issue,” Roberts stressed, “is to get more people living in town and city centres in good quality accommodation, because then that can support another kind of economy based around day-to-day living – not just going out and enjoying yourself.”

No matter what shape it takes, a night-time economy relies on a night-time workforce. Night shift workers are far more prone to having sleep disorders, gastrointestinal disorders, metabolic problems, cancer, diabetes, depression and a number of other health problems. “Our bodies and our brains are designed to function during the day and rest at night,” explained David W Ballard, head of the American Psychology Association’s Psychologically Healthy Workplace Program. “When you disrupt those natural circadian rhythms, it affects memory, reaction time, concentration, motivation and sleep patterns, and can cause chronic fatigue.” This also adversely affects work performance, leading to higher rates of accidents and errors on the job.

Labour laws vary from country to country – in the US, for instance, there are virtually no special constraints placed on overnight work, whereas in Spain, overtime is not allowed for night shift workers – but the onus is almost always on the employer to regulate night-time working conditions.

There are a number of measures employers can take to do this, Ballard said, including: mandating breaks during shifts, scheduling more demanding work for the beginning of shifts, making sure employees have access to healthy food options, installing fitness facilities on premises, providing resources for childcare and involving employees in shift scheduling decisions. In Las Vegas casinos, for instance, hourly breaks are often built into shifts, because health research shows that a higher frequency of short breaks can be more beneficial than just one long break.

“Creating a healthy work environment isn’t just a nice thing to do… it’s smart business,” Ballard insisted, since it can lead to “better product and service quality, better performance, higher levels of productivity, lower absenteeism, lower turnover rates, fewer accidents, better customer service ratings… and nowadays, many companies are concerned with keeping health care costs in check. The challenge is, the more people that are working overnight, the more support services you need.”

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