Standard Growth Scenarios Methodology

Standard Growth Scenarios allow Replica users to explore projected mobility and population data for 2035 through a series of applications. To model these standardized scenarios, Replica projected the population, employment, and work-from-home (WFH) rates for every county across the country out to 2035, and used those future-state rates as inputs into our activity-based model. We then reran our activity-based model with those future conditions to look at mobility patterns for 2035.

We used a multi-pronged approach to derive new population, employment, and WFH rates.

  1. Certain states have published their projected population and employment rate changes. Where those were available, we used states’ published forecasts as the inputs into our models.
  1. Where published data was not available, we looked at national sources (ACS for population, BEA for employment), took population and number of jobs in 2010 and 2019, drew a trend line, and extrapolated out the same trend-line to 2035.

    1. Population: ACS by county
    2. Employment: BEA by county
  2. For WFH rates, we assumed that, country-wide, 90% of people who started working from home during 2021 would still be working from home in 2035. And the number of people working from home in 2019 remains the same. (The jury is still out on whether work-from-home rates will remain stable or trend upward or downward. In fact, there is considerable debate about this topic. We are continuing to research this topic so that we can better tune our models as clearer patterns and a stronger consensus emerge.)