Housing Crisis in the Bay Area

Introduction:

When deciding where to relocate to in the Bay Area due to new employment or returning to in-person classes, we wanted to take a more in-depth look into how drastically rents have changed over the years. Using the San Francisco rents data set, we wanted to look into San Francisco’s counties to see which county had the least average increase in rent over the years. Specifically, which counties in San Francisco have had a reasonable monthly moving average rent from 2000 to 2018? 2.

Data Description:

The data set we decided to use is, rent.csv, which we found through tidytuesdays on [GitHub] (https: //github.com/rfordatascience/tidytuesday/tree/master/data/2022/2022-07-05)). This data set contains 200796 rows, and 17 columns [200796 x 17]. From the 17 variables in our data set related to the rents in San Francisco, the variables of interest were:

• Price ( In Dollars ): Integer, Quantitative - Discrete

• Year: Integer, Quantitative - Discrete

• County: Character, Categorical - Nominal

Response Variable - Price

Predictive Variable - Year

Results:

We started by plotting the average monthly rent in San Francisco from the year 2000 through the year 2018, to observe a linear relationship between the predictive variable years and response variable average monthly rent.

Data Cleaning:

In order to calculate the monthly rent within those the counties of San Francisco (table above), we grouped our data by the counties and the years that these rental spaces were posted on Craigslist in San Francisco. This process allowed us to see a general image of our data and allowed us to create a linear model for the relationship between the average monthly price of rents and years as seen on Figure 1.

From observing the scatter plot above, we notice that as the years pass, there is a resulting increase in the average monthly rent in all San Francisco counties. The “aquamarine” line shows us the moving average of average monthly rent throughout the years, and the “blue” shading indicates the confidence interval where 95% of the average monthly rents are contained with the data set of San Francisco rents. Furthermore, from our observations, we wanted to identify if year was a significant factor of increase in average monthly rents.

From our linear model, we see that year is a statistically significant predictive variable because it has a p-value of less than α = 0.05, meaning that over the years there has been an increase in average monthly rent in San Francisco.

After observing that year is a significant predictor in the monthly average rents in San Francisco, we wanted to extrapolate which counties had the most reasonable monthly average rent throughout the years of 2000 to 2018.

After dividing the data based on county, we notice that there have been drastic changes in rent in counties such as Napa, San Francisco, and Marin. In contrast, other counties such as San Mateo, Santa Clara, Santa Cruz, and Sonoma, have gradually increased their average monthly rents. Here we can see the list of those Counties in San Francisco, where the average monthly rents have gradually increased from 2000 to 2018. As we can see, the range in pricing between these counties is $1871.63 to $2,828.82 in 2018.

Counties where rent is reasonable being under $3000

From our observations, Solano, Contra Costa, and Santa Cruz are the counties with the lowest moving monthly rents at $1871.63, $2257.19, and $2276.43, respectively, making them the most reasonable places to relocate in all of the San Francisco counties.