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Set of different market structure measures to reflect a given market structure.

Usage

concstats_mstruct(x, type = c("firm", "nrs_eq", "top", "top3", "top5",
 "all"), na.rm = TRUE, digits = NULL)

Arguments

x

A non-negative numeric vector.

type

A character string of the measure to be calculated, can be abbreviated with the first letter. Defaults to "firm". Input is not case-sensitive.

na.rm

A logical vector that indicates whether NA values should be excluded or not. Must be either TRUE or FALSE. The default is TRUE. If set to TRUE the computation yields a message if the vector contains NA values. NAs will be removed for further computations. If set to FALSE with NAs present the computation yield NA.

digits

A non-null value for digits specifies the minimum number of significant digits to be printed in values. The default is NULL and will use base R print option. Significant digits defaults to 7. Values are restricted between 1 and default value.

Value

A single calculated numeric measure or data frame.

Details

  • concstats_mstruct is a wrapper for the proposed structural measures.

  • concstats_firm(), returns the number of firms with a given market share.

  • concstats_nrs_eq() computes the reciprocal of the HHI, which indicates the equivalent number of firms of the same size.

  • concstats_top(), concstats_top3(), and concstats_top5() calculate the cumulative share of the top (top 3 and top 5) firm(s) and returns the value in percentage.

  • concstats_all_mstruct() computes all measures in a one step procedure. All measures can be computed individually.

  • concstats_top_df(), concstats_top3_df(), and concstats_top5_df() are slight variations. Firm id or ranking might be of interest. In this case an additional id or firm variable is needed. The functions will return a data frame. These functions are just individually accessible.

Note

The vector of market shares should be in a decimal form corresponding to total shares of individual firms/units.The sum of the vector should sum up to 1. Alternatively, the user might use concstats_shares() to converting raw variables, e.g. loans or sales into shares.

Examples

# a vector of market shares
x <- c(0.35, 0.4, 0.05, 0.1, 0.06, 0.04)
concstats_mstruct(x, type = "firm", digits = 1)
#> [1] 6

# Calculate the market structure group measures
concstats_mstruct(x, type = "all", digits = 2)
#>          Measure     Value
#> 1          Firms  6.000000
#> 2 Nrs_equivalent  3.331113
#> 3        Top (%) 40.000000
#> 4       Top3 (%) 85.000000
#> 5       Top5 (%) 96.000000