# Getting started

## What is concstats?

concstats is a small package that helps you to calculate the structure, concentration or diversity measures of a given market.
You can reach that goal in different ways:
a) calculating an individual measure, e.g. the Herfindahl Hirschman Index (HHI) or its dual.
b) calculating a group of measures, e.g. structural measures, or
c) a set of pre-selected measures in a one-step procedure.

## How can you install it?

You can install `concstats` directly from CRAN

    install.packages("concstats") # Market Structure, Concentration, and Inequality
                                  # Measures
    library(concstats)

You can install the development versions from

r-universe
install.packages(“concstats”, repos = “https://ropensci.r-universe.dev”)

github (requires `remotes` or `devtools`)
remotes::install_github(“ropensci/concstats”

# Why did I build it?

Measures of concentration and competition are important and give a first insight of a given market structure in a particular market.
They are important to determine public policies and strategic corporate decisions. However, in research and in practice the most commonly used measure is the Herfindahl Hirschman Index. The `concstats` package offers a set of alternative measures.

`concstats` allows you to calculate quickly a particular measure or a group of measures to give you a better overview of a given market situation and therefore reducing uncertainty. It can be used by practitioners and academics alike.

## How can it be used?

`concstats` should be used by practitioners and academics who are concerned about structure, concentration, diversity or inequality in general or on a regular basis. A single standard measure like the Herfindahl Hirschman Index (HHI) may lead to erroneous conclusions. The `concstats` package offers a straightforward way to calculate standard and alternative measures given a data set of market participants and their participation (in relative values) in a particular market at a given point of time or over time. concstats provides currently the following basic functions:

- `concstats_concstats()` calculates eight pre-selected measures in a one-step procedure to provide a first insight of the market. The resulting data frame contains eight measures, which are: number of firms with market share, numbers equivalent, the cumulative share of the top (top 3 and top 5) firm(s) in percentage, the hhi index, the entropy index, and the palma ratio.
- `concstats_mstruct()` is a wrapper for the following measures: firm, nrs_eq (Numbers equivalent), top, top 3 and top 5 market share, and all calculates all measures as a group. Each of the measures within a group can be accessed directly using the prefix concstats_, e.g. concstats_firm.
- `concstats_comp()` is a group wrapper for the following concentration measures: hhi, the dual of the hhi, the min. of the hhi, the dominance index, the stenbacka index, and finally all which calculates all measures as a group.
- `concstats_inequ()` is a wrapper for inequality and diversity measures and contains: entropy, gini coefficient, simpson index, the palma ratio and the alternative grs measure, all calculates the group measures.