How do workers move up the corporate ladder and how can they maximize their career mobility? Increased wealth disparity, increased job polarization, and decreases in absolute income mobility (i.e. the fraction of children who earn more than their parents) all suggest that upward mobility is difficult for today’s workers. It’s as if the rungs on the ladder to career success are there for some and absent for others. But who is stuck, and why?
By conventional wisdom, education determines a worker’s entry into the labor force. Workers who start higher up on the ladder have a better chance of reaching the top. However, returns on higher education have not kept pace with growing costs and mid-career workers are generally unwilling to return to school.
Instead, most workers utilize their existing knowledge, ability, and skills — along with social connections— to advance their careers. That is, a worker is more likely to fill a job opening if their capabilities meet the job’s requirements. These capabilities more aptly represent the rungs on the corporate ladder, which are present for some and absent for others.
This theory of skills is not new and skill matching has long been considered a key mechanism in the job matching process (just ask the winners of the 2010 Nobel Prize in Economics). Earlier studies of job polarization and limited career mobility have taken note and focused on different types of labor. For example, Daron Acemoglu and David Autor measure the annual wages of occupations and observe a “hollowing of the middle class,” which they describe as growing employment share for low- and high-skill employment at the expense of middle-skill employment. They argue that high-skill employment leverage cognitive skills, while low-skill employment rely more prominently on physical skills.
These cognitive and physical labor categories — in addition to traditional measures of education and wage — are very broad. For example, consider that Civil Engineers and Medical Doctors are both professions that fall into the same conventional labor categories; they both have high educational requirements, make high wages, and require cognitive non-routine labor. Yet, their skill sets are largely non-transferable. To explain why Civil Engineers are unlikely to become Medical Doctors — and to explain where skill sets might limit other workers’ career mobility — we need a higher resolution framework for specific workplace skills.
Our study answers this call for a better resolution into workplace skills. Rather than focusing on broad expertly-derived skill categories, we employ a completely data-driven approach using high-resolution occupational skill surveys carried out by the US Department of Labor. By examining how pairs of skills co-vary in importance across occupations and controlling for ubiquitous skills, we identify pairs of skills with high complementarity. Skill pairs exhibiting complementarity tend to support each other by boosting the productivity of workers who possess both skills, or by the ease of acquiring skills simultaneously. For example, Mathematics and Programming have high complementarity, but Programming and Explosive Strength do not.