For many companies, hiring full-time employees has become a last resort, reserved for tasks that cannot be automated or outsourced or handed to an independent contractor. The goal is to keep the number of full-time employees as small as possible — and a key reason is that the government requires companies to take care of employees. Companies, in other words, are seeking to minimize the number of workers who must be treated fairly.

Google appears to be a leader in this field. Daisuke Wakabayashi of The Times reported this week that fewer than half of the people who work for the giant technology company are conventional full-time employees. Google has about 102,000 of those full-time employees and about 121,000 “TVCs,” a company term for temps, vendors and contract workers.

The use of contract labor is neither new nor inherently objectionable . Allowing short-term contracts for discrete projects can serve the needs of companies and workers. There is also clear logic in hiring specialized businesses to provide cleaning services or workplace security, just as companies have long paid other companies to market products or to provide hotel rooms. The Times, like most large American companies, uses contractors, including freelance writers.

But the reliance on contractors is only partly motivated by the benefits of specialization.

Companies like contractors because contractors are cheap. The staffing company OnContracting estimates that using contract workers rather than full-time employees can save tech companies an average of $100,000 per year per job. Such workers are paid less; receive fewer benefits; require less investment, for example in training; and impose fewer obligations. Companies generally do not contribute to the cost of health insurance for contract workers, nor do they contribute to retirement plans. Contract workers do not accrue vacation days, and they are usually not eligible for parental or medical leave. They can be let go at any time.