ffs_rates: Estimation of bilateral migrant flows from bilateral migrant...

In migest: Methods for the Indirect Estimation of Bilateral Migration

Estimation of bilateral migrant flows from bilateral migrant stocks using rates approaches

Description

Estimates migrant transitions flows between two sequential migrant stock tables using approached based on rates.

Usage

ffs_rates(stock_start = NULL, stock_end = NULL, M = NULL, method = "dennett")

Arguments

stock_start	Matrix of migrant stock totals at time t. Rows in the matrix correspond to place of birth and columns to place of residence at time t
stock_end	Matrix of migrant stock totals at time t+1. Rows in the matrix correspond to place of birth and columns to place of residence at time t+1.
M	Numeric value for the global sum of migration flows, used for dennett approach.
method	Method to estimate flows. Can take values dennett or rogers-von-rabenau. See details section for more information. Uses dennett as default.

Value

Estimates migrant transitions flows based on migration rates.

When method = "dennett" migration are derived from the matrix supplied to stock_start. Dennett uses bilateral migrant stocks at beginning of period. Rates then multiplied by global migration flows supplied in M.

When method = "rogers-von-rabenau" a matrix of growth rates are derived from the changes in initial populations stock stock_start to obtain stock_end;

P^{t+1} = g P^{t}

and then multiplied by the corresponding populations at risk in stock_start. Can result in negative flows.

Author(s)

Guy J. Abel

References

Dennett, A. (2015). Estimating an Annual Time Series of Global Migration Flows - An Alternative Methodology for Using Migrant Stock Data. Global Dynamics: Approaches from Complexity Science, 125–142. https://doi.org/10.1002/9781118937464.ch7

Rogers, A., & Von Rabenau, B. (1971). Estimation of interregional migration streams from place-of-birth-by-residence data. Demography, 8(2), 185–194.

See Also

ffs_demo, ffs_rates

Examples

s1 <- matrix(data = c(100, 10, 10, 0, 20, 55, 25, 10, 10, 40, 140, 65, 20, 25, 20, 200),
             nrow = 4, ncol = 4, byrow = TRUE)
s2 <- matrix(data = c(75, 25, 5, 15, 20, 45, 30, 15, 30, 40, 150, 35, 10, 50, 5, 200),
             nrow = 4, ncol = 4, byrow = TRUE)
r <- LETTERS[1:4]
dimnames(s1) <- dimnames(s2) <- list(pob = r, por = r)
s1; s2

# calculate total migration flows for dennett approach
n <- colSums(s2) - colSums(s1)

ffs_rates(stock_start = s1, M =  sum(abs(n)), method = "dennett" )
ffs_rates(stock_start = s1, stock_end = s2, method = "rogers-von-rabenau" )

migest documentation built on Nov. 18, 2023, 9:06 a.m.