The data visualized in this document comes from the GitHub site maintained by the New York Times: https://github.com/nytimes/covid-19-data. Please see the site for a description of how data is obtained.

This visualization was constructed with data downloaded on

## [1] "2021-01-27"

The latest date contained in the file was

## [1] "2021-01-26"

Cases and mortality across the USA

We start by looking at States level data. Total cases and death counts give us a sense of the size and scale of the epidemic.

As for the case of Italy, it seems that not every portion of the country is equally affected by the epidemic. To make sure that the differences we see are not due to variable population sizes across states, we look at the same data relative to population counts.

This indeed produces some “reordering”, but states continue to look heterogeneous in terms of how severely impacted they are from the epidemic, and New York State and New Jersey remain the most affected.

Daily increments in few states

To understand the direction of the epidemic is taking, it is useful to look at daily increments. In the interest of legibility, we focus on few states, selected among the most severely impacted.

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The states analyzed, as of May 30, had experience a decline in new cases, with the exception of California.

A closer look to New York

The experience of Italy, suggests that we expect to see variability on the severity of the epidemic on a scale finer than states. To explore if this is the case in the US as well, we look at the profiles of cases and deaths in the different counties of the most affected state, New York state. Every county is represented with a different color. The NYT reports aggregate values for the five counties that correspond to the five boroughs of New York City and do not have functioning county governments: New York (Manhattan), Kings (Brooklyn), Bronx, Queens and Richmond (Staten Island). The population of NYC is approximalety 8.3 million. The population of the State of New York is approximately 19.4 million (so that NYC houses a little over 40% of the state population). The vast majority of cases and deaths in New York State are concentrated in NYC (cyan points in the plots below). The other counties with higher case numbers are Nassau, Suffolk and Westchester, all geographically close to NYC.

Focusing on California

We now turn attention to California, the state where Stanford University is located and where I live. As for New York, we look at variability across counties. We identify with color some counties, and also look at data on their population to put the counts of COVID-19 cases and deaths in context.

Southern California

To look at daily increments we focus on the counties surrounding Los Angeles which have highest number of cases.

Bay Area

We now focus on the bay area counties, representing the area surrounding Stanford University, where I live.