An extensive literature has documented the association of psychosocial work stressors – e.g., job strain, effort-reward imbalance, organizational injustice, long working hours, job insecurity, shift work, workplace harassment and bullying – with mental health problems^1-4. However, the implications for population mental health of the changing nature of work in the 21st century have not been sufficiently highlighted.

The classical job strain model captures job task-related exposures (e.g., the combination of excessive psychological demands with lack of autonomy), but does not speak to the broader picture of what has been happening in the workplace during the era of globalization, automation, and the rise of alternate forms of work (e.g., casual and part-time work). Three trends are exemplary in this respect: digital enforcement, just-in-time scheduling, and workplace fissuring. Each of these trends represents a potential social determinant of mental health at the population level.

Digital surveillance has become widespread across workplaces in some countries, whether in the form of tracking devices worn by employees in Amazon warehouses (“fulfillment centers”) to meet their daily quotas, or the monitoring software installed on the desktop computers of remote employees during the pandemic.

One of the most intensely surveilled occupations in the US is trucking, which employs about 3 million drivers. Truck drivers are already at high risk of mental health problems, due to the excessive hours of work, lack of sleep, and social isolation⁵. Since the deregulation of the US trucking industry in the 1980s, they have also had to contend with the burden of low wages, due to a shift in compensation from salaried work to piece rate compensation. Truck drivers are paid for miles driven, not for the hours they spend on the road stuck in congested traffic or the hours waiting for their cargo to be loaded/unloaded. As a result of the switch to piece rate compensation, truckers’ wages dropped by 44% between 1977 and 1995⁵.

In order to make a living, drivers have been forced to spend longer hours on the road, which increases the risk of accidents. In response, lawmakers in 1997 mandated the installation of electronic logging devices on all trucks. These devices have helped to enforce “hours of service” regulations in the trucking industry, which dictate that truckers may drive no more than eleven hours a day, after which they must take a mandatory rest break. However, despite the industry-wide improvement in compliance with hours of service limits, the introduction of digital enforcement paradoxically increased the rate of crashes, because drivers responded by speeding to make up for lost productivity⁶.

In terms of worker autonomy, the same time-logging devices are bundled with other capabilities which enable employers to monitor driver performance in areas such as fuel usage, frequency of changing lanes, and adherence to travel routes. This has nothing to do with compliance with safety regulations, but is all about extracting efficiency and maximizing productivity.

The concept of just-in-time scheduling originally began as a management strategy in the manufacturing sector to align the delivery of raw-material supplies with production schedules. Subsequently it spread to the retail and service industry, where employers use it to manage labor costs by scheduling employees based on fluctuating consumer demand. For example, if a store manager believes that his/her shop will be unusually busy ahead of a national holiday, he/she can update scheduling on the fly and ask additional employees to come in.

Under just-in-time scheduling, workers typically receive their schedules on short notice, and may have their shifts changed or canceled at the last minute. Employers may put workers on call with no guarantee that there will be work available for them. According to the American Time Use Survey, an estimated 45% of wage and salary workers over the age of 15 are given their schedules less than a month in advance, while 20% are told about their schedules less than one week in advance⁷.

In addition to making it difficult to arrange childcare, attend school, or hold a second job, irregular work hours also result in income volatility for hourly wage workers. Variable work hours in turn jeopardize access to many safety net programs (e.g., food assistance programs in the US) which require a minimum number of hours of work per week. A study in South Korea found that workers with unpredictable work hours had a significantly increased risk of depressive symptoms⁸.

A third example of the changing nature of work is workplace fissuring, which refers to the management practice of outsourcing parts of the organization which are not viewed as “core competencies” of the firm⁹. For example, most cleaners, laundry workers and kitchen staff in the hotel industry are not employees of the brand-name hotels, but are “independent contractors” hired by third party companies. Customer service departments of major corporations have been spun off to third party companies, which in turn hire an army of independent contractors to perform the work. The independent contractor is responsible for purchasing the assets required to perform the work (home office equipment such as a computer, headsets and a dedicated phoneline), and must pay for the costs of training to become a customer service representative for the brand name corporation, as well as pay a monthly fee to use the digital platform that connects him/her to customers.

At the same time, the independent contractor classification means that the worker receives none of the benefits of being a salaried employee, such as a pension or health insurance. These workers are typically paid for the time they spend responding to customer calls, not for the hours waiting for customers to call in. An estimated 1 in 5 people in the US workforce are engaged in the fissured workforce – including hotel and hospitality, telephone operators, home health care, janitors, security guards, and fast food restaurants.

The consideration of working conditions as a social determinant opens up the possibility for an expanded set of structural interventions to promote population mental health, e.g., changing laws to protect the rights, welfare and safety of employees. It forces the question: what is the role of corporations and employers in generating mental ill-health, and what is the potential for work-based interventions, policies and regulations to promote mental health? Businesses (and shareholders) profit from wringing maximum productivity out of workers through low pay, long work hours, unpredictable schedules, digital surveillance, and shifting the costs of doing business on to workers. Consumers also benefit from lower prices, but, in many cases, consumers are also workers being exploited by the same system.

It is time for us to consider the changing nature of work in the 21st century as a significant social determinant of mental health, and to make a substantial effort to develop interventions addressing it.

大量文献记录了心理社会工作压力源（例如工作压力、努力回报失衡、组织不公正、工作时间长、工作不安全感、轮班工作、工作场所骚扰和欺凌）与心理健康问题的关联^1-4 。然而，21 世纪工作性质变化对人口心理健康的影响尚未得到充分重视。

经典的工作压力模型捕捉到了与工作任务相关的暴露（例如，过度的心理需求与缺乏自主性的结合），但没有涉及全球化、自动化、自动化时代工作场所所发生的更广泛的情况。替代工作形式（例如临时工作和兼职工作）的兴起。在这方面，三个趋势堪称典范：数字化执行、及时调度和工作场所分裂。这些趋势中的每一个都代表了人口层面心理健康的潜在社会决定因素。

在一些国家，数字监控已在工作场所广泛普及，无论是亚马逊仓库（“配送中心”）员工为完成每日配额而佩戴的跟踪设备，还是在远程员工的台式电脑上安装的监控软件。大流行。

美国监控最严格的职业之一是卡车运输业，该行业雇用了约 300 万司机。由于工作时间过长、睡眠不足和社交孤立，卡车司机已经面临心理健康问题的高风险⁵ 。自 20 世纪 80 年代美国卡车运输业放松管制以来，由于薪酬从带薪工作转向计件薪酬，他们还必须应对低工资的负担。卡车司机的报酬是按行驶里程计算的，而不是按他们在交通拥堵的道路上花费的时间或等待货物装卸的时间计算的。由于转向计件工资，卡车司机的工资在 1977 年至 1995 年间下降了 44% ⁵ 。

为了谋生，司机被迫在路上花费更长的时间，这增加了发生事故的风险。作为回应，立法者于 1997 年强制要求在所有卡车上安装电子记录设备。这些设备有助于执行卡车运输行业的“服务时间”规定，该规定规定卡车司机每天的驾驶时间不得超过 11 小时，之后必须强制休息。然而，尽管整个行业在遵守服务时间限制方面有所改善，但数字执法的引入却反而增加了事故率，因为司机的反应是超速，以弥补生产力损失⁶ 。

在工人自主权方面，同样的时间记录设备与其他功能捆绑在一起，使雇主能够监控驾驶员在燃油使用、变道频率以及遵守行驶路线等方面的表现。这与遵守安全法规无关，而是为了提高效率和最大化生产力。

准时制调度的概念最初是作为制造业的一种管理策略，旨在使原材料供应的交付与生产计划保持一致。随后，它蔓延到零售和服务行业，雇主利用它根据不断变化的消费者需求安排员工来管理劳动力成本。例如，如果商店经理认为他/她的商店在国庆节前会异常繁忙，他/她可以即时更新日程安排并要求更多员工进来。

在准时制安排下，员工通常会在短时间内收到日程安排，并且可能会在最后一刻更改或取消轮班。雇主可以让工人待命，但不能保证他们会有工作。根据美国时间使用调查，估计 45% 的 15 岁以上工资和薪水工人提前不到一个月就得知了自己的日程安排，而 20% 的人提前不到一周就得知了自己的日程安排⁷ 。

除了难以安排儿童看护、上学或从事第二份工作外，不规律的工作时间还会导致小时工资工人的收入波动。可变的工作时间反过来又会危及许多安全网计划（例如美国的食品援助计划），这些计划要求每周至少工作时数。韩国的一项研究发现，工作时间不可预测的工人出现抑郁症状的风险显着增加⁸ 。

工作性质变化的第三个例子是工作场所裂痕，它是指将组织中不被视为公司“核心能力”的部分外包的管理实践⁹ 。例如，酒店行业的清洁工、洗衣工、厨房工等大部分都不是品牌酒店的员工，而是第三方公司聘用的“独立承包商”。大公司的客户服务部门已被剥离给第三方公司，而第三方公司又雇用一大批独立承包商来执行这项工作。独立承包商负责购买执行工作所需的资产（家庭办公设备，如计算机、耳机和专用电话线），并且必须支付成为品牌公司客户服务代表的培训费用，以及支付月费以使用将他/她与客户联系起来的数字平台。

同时，独立承包商分类意味着工人无法享受受薪雇员的任何福利，例如养老金或健康保险。这些工人的工资通常是根据他们响应客户电话所花费的时间，而不是等待客户来电的时间计算的。据估计，美国劳动力中有五分之一的人属于裂痕劳动力——包括酒店和酒店业、电话接线员、家庭保健、门卫、保安和快餐店。

将工作条件视为社会决定因素，为扩大结构性干预措施以促进人口心理健康提供了可能性，例如修改法律以保护员工的权利、福利和安全。它提出了一个问题：企业和雇主在产生心理疾病方面发挥了什么作用，基于工作的干预措施、政策和法规在促进心理健康方面的潜力有多大？企业（和股东）通过低工资、长时间工作、不可预测的时间表、数字监控以及将业务成本转嫁到工人身上，从工人身上榨取最大生产力来获利。消费者也受益于较低的价格，但在许多情况下，消费者也是受到同一制度剥削的工人。

我们现在应该将 21 世纪不断变化的工作性质视为心理健康的重要社会决定因素，并大力制定干预措施来解决这一问题。