technicians, broadcast engineers, technical writers, and materials scientists are examples. Although many technician occupations that have arisen de novo center on the maintenance of a technology, not all of them do. For instance, sonographers rarely repair ultrasound equipment, yet their work arose with the use of ultrasound in medical imaging (Barley, 1990). Technicians who monitor the controls of nuclear power plants and EEG technologists are further examples of occupations spawned by new technologies that have little role in the technology's maintenance.
Ironically, technological change has also augmented the professional and technical labor force by automating blue-collar and lower white-collar jobs. Computerized technologies typically automate the most routine parts of a job simply because routines are easier for designers to program. To successfully deskill or eliminate workers via automation, firms must also reallocate the more complex aspects of a target occupation's work to another occupation. Since the occupations that benefit from such reallocations tend to acquire cognitive and technical responsibilities, deskilling unintentionally expands the number of technical workers. For instance, Smith (1987) has argued that a reallocation of tasks once exercised by craftsmen and foremen was largely responsible for the birth of such technician occupations as rate-fixers, estimators, and inspection and planning engineers. Similar arguments have been made for the rise of programmers and schedulers in machine shops (Braverman, 1973).
Even when skills are not reallocated, automation may still skew a firm's labor force toward technical and other highly skilled employees, if the employment of unskilled and semiskilled labor declines disproportionately (Spenner, 1995). Several researchers have shown that two decades of computerization have altered the mix of jobs in the insurance and banking industries by precisely such a path (Baran, 1987; Attewell, 1987, 1992). Although office automation enabled firms to reduce their reliance on lower-level clerks, the relative importance of more highly skilled workers (particularly those who program and maintain computers and databases) increased as the number of clerical employees fell. Thus, when computerized automation occasions layoffs among lower-skilled workers, it leaves in its wake a work structure more heavily weighted toward members of professional and technical