2020 Census block weights (population as share of overall block group)

data.table for use in EJAM

Details

See EJAM package for more info.

Created by census2020_get_data() and census2020_save_datasets()

This package can create this data table but does not store it.

Rows: 8,174,955

Columns:

• blockid (for joins among tables blockwts, blockpoints, quaddata, blockid2fips) unique integer 1 through number of rows (blocks), used as a more efficient ID than a 15-character FIPS code.

• bgid The unique ID of the block group that contains this block

• blockwt is used by EJAM package function doaggregate() to summarize the block group score of the average person in some location such as within 1 mile of a point, as the population weighted mean of blockgroup scores of all the blocks in the area. blockwt is the block's population weight, calculated as the block population as a fraction of the parent blockgroup pop. Based on the latest decennial Census table of population count for each block. This table of weights can be used for calculating the weighted mean or sum of each blockgroup score for a buffer where only some blocks of any given blockgroup are in the buffer. The sum of weights from some blocks tells you what fraction of its whole parent blockgroup's population count is in those blocks (the ones found inside a buffer, for example).

• block_radius_miles is the effective radius of a block, where pi times that radius squared is the block area in square miles. This gets used to adjust distances of sites at very short distances to the internal point.