Network Methodology

Overview

This network visualization shows how central certain occupations are in the U.S. economy, including the intensity of foreign-born workers present in each occupation.

The network relies on the complementarity between occupations. Two occupations are connected when they are highly complementary to each other, which we measure as those two occupations having a higher probability of working in the same industry and tending to grow (or shrink) together over time relative to all occupations in that industry.

Methodology

Occupational Complementarity

We characterize two occupations as being complementary if their employment shares move in the same direction within industries over time. To construct this measure, we use Lightcast Staffing Patterns Data to first calculate the change in the share of employment in each occupation within industries over the period 2009 to 2019.

Next, for each occupation, we calculate the pairwise correlation between changes in its employment share and the employment shares of all other occupations. As an example, we find that the complementarity between "food and beverage serving workers" and "cooks and food preparation workers" is 0.49. This number indicates that in at least 49 percent of industries when either of the two occupations was both present and one of them grew (or shrank) as a share of total employment the other one also grew (or shrank).

Occupations are considered complementary if their industry employment shares co-vary together.

Network Visualization

For the visualization, we show links between occupations when their complementarity measure exceeds 55%. More central occupations have many connections and are naturally pulled to the center by the force-directed layout algorithm.

Node colors indicate the share of immigrant workers in each occupation (darker blue = higher share). Node sizes reflect total employment levels.

Data Sources

For more detailed information about methods, measures and data, refer to Bahar and Wright (2023).