relatedness_density_ext {EconGeo}

Compute the relatedness density between regions and industries that are not part of the regional portfolio from regions - industries matrices and industries - industries matrices

Description

This function computes the relatedness density between regions and industries that are not part of the regional portfolio from regions - industries (incidence) matrices and industries - industries (adjacency) matrices

Usage

relatedness_density_ext(mat, relatedness)

Arguments

mat

An incidence matrix with regions in rows and industries in columns

relatedness

An adjacency industry - industry matrix indicating the degree of relatedness between industries

Value

A matrix representing the relatedness density between regions and industries that are not part of the regional portfolio. The values in the matrix indicate the share of industries related to each industry in each region, scaled from 0 to 100. Rows represent regions and columns represent industries. Industries that are part of the regional portfolio are assigned NA.

Author(s)

Pierre-Alexandre Balland [e-mail]

References

Boschma, R., Balland, P.A. and Kogler, D. (2015) Relatedness and Technological Change in Cities: The rise and fall of technological knowledge in U.S. metropolitan areas from 1981 to 2010, Industrial and Corporate Change 24 (1): 223-250

Boschma, R., Heimeriks, G. and Balland, P.A. (2014) Scientific Knowledge Dynamics and Relatedness in Bio-Tech Cities, Research Policy 43 (1): 107-114

See Also

relatedness, co_occurrence

Examples

## generate a region - industry matrix in which cells represent the presence/absence of a RCA
set.seed(31)
mat <- matrix(sample(0:1, 20, replace = TRUE), ncol = 4)
rownames(mat) <- c("R1", "R2", "R3", "R4", "R5")
colnames(mat) <- c("I1", "I2", "I3", "I4")

## generate an industry - industry matrix in which cells indicate if two industries are
## related (1) or not (0)
relatedness <- matrix(sample(0:1, 16, replace = TRUE), ncol = 4)
relatedness[lower.tri(relatedness, diag = TRUE)] <- t(relatedness)[lower.tri(t(relatedness),
  diag = TRUE
)]
rownames(relatedness) <- c("I1", "I2", "I3", "I4")
colnames(relatedness) <- c("I1", "I2", "I3", "I4")

## run the function
relatedness_density_ext(mat, relatedness)