I am doing Sub2 bootcamp now and we had a task to analyze the population of the backyard market. I didn't find data in a form I like so I pulled out data from the census and did my own research. The goal of the research is to find promising markets - cities with large populations which growing. Pace considered markets with year population growth >= 0.8% as good markets. I did an analysis for the largest cities in MA and present it here. My script is available by the link below so you can play with it and present data as you want.

I used data sets

* https://www2.census.gov/programs-surveys/popest/datasets/2010-2020/cities/SUB-EST2020_25.csv

* https://www2.census.gov/programs-surveys/popest/datasets/2020-2022/cities/totals/sub-est2022_25.csv

This is a link to my notebook

* https://colab.research.google....

Data 2010 - 2020

I filtered out MA cities with small populations and left only cities having populations larger than 80k in 2012. There are only 11 such cities. I plotted population growth by years, and I found:

* Boston and Cambridge are the only cities having a population growth of more than 1% per year. The trend for Boston is that population growth decreases s.t. in 2012 it had a growth of about 2% but in 2018 it became smaller than 1%. Cambridge has had large fluctuations of population growth over the years but I would say on average it has growth 1%.

* Majority of cities had a population growth of about 0.5% in the first half of the 2010s

* All cities have a trend of decreasing population growth

* Springfield had a small growth in the first half of 2010s (population is 154620 people in 2015) and in the second half of 2010s, its population declined (population 152646 in 2020).

* In 2018 population in Newton City and Lower City started to decline. These sites together with Springfield are the only ones with a declining population this year which seems to be the start of the new trend. There are not enough data though to argue it clearly.

* In 2020, the middle of the online era, most of the cities had declining or small growing (Cambridge, Fall River, and New Bedford) populations.

Data 2020-2022

In this data set census changed methodology so comparing this data set with the previous one is not straightforward and could lead to misleading results. That is why I don't have data points for 2020 and don't plot both data on the same figure.

For this dataset, I considered MA cities with populations larger than 85k people as I wanted to keep the number of cities small. These are my findings:

* In 2021 almost all cities had a declining population.

* In 2021 the only city that has a growing population is Worcester. It seems people were moving to Worcester from other big cities. The absolute number does not allow us to conclude that people were moved to Worcester from all of MA, as the population in Worcester grew up only by 600 people in 2021. But there is something in this city preventing people from move out (or stimulating other people to move in to compensate those who were leaving)

* In 2022 there are only two cities with a growing population Quincy and Cambridge. Growth is large compared to what these cities had in a pre-pandemic era so I don't think that it's fluctuations rather than new trends. It is not enough data to argue it but I would assume that people started moving back to cities around Boston.