Proportion data has values that fall between zero and one. Consequently, the indexed value of x must also increase 100 percent, from 100 to 200. The hhi of a market is calculated by summing the squares of the percentage market shares held by the respective firms. Businesszeal will tell you how to calculate the herfindahlhirschman index hhi. Stata module to generate herfindahlhirschman index hhi variables. Constructing a postal codespecific herfindahlhirschman index applying stata software article january 2011 with 37 reads. This module should be installed from within stata by typing ssc install hhi5.
Herfindahlhirschman index in stata 11 may 2016, 07. Full text developmental origins of health and disease. Computing herfindahlhirschman index hhi with unbalanced panel data. Association of hospital market concentration with costs of. Dear antoine, the second option is better and worked. The impact of product market competition on debt ratio in vietnam stock market tan vinh nguyen, academy of politics region. Development of competition indicators in the norwegian general practice.
I computed the hhi index manually and have attached it as a third column to show the results that i would like to have. The value of the hhi index ranges from 0 pure competition to 1 pure monopoly, and a higher hhi value indicates a highly concentrated market. From a policy perspective, hhi is an important measure, given that it is used by the department of justice to evaluate potential mergers u. Syed basher qatar national food security program on wed, 12810, nick cox. The economic problem indexing is kind of like a race. The differences in global hope score and mean scores on individual items from 3 to 12 months were small and not statistically significant, and only results from 12 months are shown table 2. Feb 11, 2020 the herfindahlhirschman index hhi is a commonly accepted measure of market concentration. Stata module to calculate charlson index of comorbidity. Statistical software components from boston college department of economics.
Automated indexing software, a tool that now accompanies most wordprocessing software, build a concordance or a word list, from processed files. Between 2000 and 2001, variable x increased from 250 to 500, or 100 percent. I agree that it does not make much sense to have a dataset with one observation so you may want stata to display the value of the index in the results. We will include the robust option in the glm model to obtain robust standard errors.
When i calculate the hhi from market shares, i get a time series of hhi for a 25 years and not for all firms to be used in panel. The greater the index is, the more the market share. The number of hospitals in each area and the hhi varied within conditions by different definition of market figure 3, panels ae. It contains inbuilt modules that can help compute the hhi. Stata module to generate herfindahlhirschman index hhi. If the software is correctly installed on your computer clicking the link above starts up the software and opens the. I am using the panel data where i have 10 years of time, 50 states, in. Its capabilities include a broad range of statistical analyses, plus data management, graphics, simulations, and custom programming.
In addition, the research also adds model also incorporates control variables that may affect debt ratio. File indexing software wincatalog 2019 will scan disks hdds, dvds, and other or just specific folders you want to index, index files, and create an index of files wincatalog will automatically index id3 tags for music files, exif tags and thumbnails for image files and photos, thumbnails and basic information for video files, contents of archive files, thumbnails for pdf files, iso. How to index any economic data series to a common starting point to facilitate the comparison of numeric data. On april 23, 2014, statalist moved from an email list to a forum, based at. Stata is a generalpurpose statistical analysis package created and maintained by statacorp lp. The module supports multiple variables and group ids and allows user to export output in table format csv comma delimited. It allows user to generate new hhi variables for large data panels and export output in table format. It is calculated by squaring the market share of each firm competing in a market and then summing the. The index was calculated on all hospitalization records of resident population in 2008 using an ad hoc algorithm developed with the stata software. Constructing a postal codespecific herfindahlhirschman index applying stata software article.
The advantages of the herfindahl index are that it reflects more firms in the industry and it gives greater weight to the companies with larger market shares. Hospital market concentration was assessed using a variableradius herfindahlhirschman index hhi in the 2003, 2006, and 2009 hospital market structure files. Stata module to compute herfindahl index ideasrepec. That a racehorse can run is relatively uninteresting. Computing herfindahlhirschman index hhi with unbalanced. Thus the indexed value of y increased 50 percent, from 100 to 150, over the same time period indexing allows you to quickly gauge percentage changes.
Figure 3 shows the measures of competition in each area centred on hospital location panels ae and the concordance with providers ramr panels fj. One measure of competition in an industry is via concentration ratios. First, before we calculate hhi using stata, install the package. Department of justice, the federal trade commission, and state attorneys general have used the herfindahlhirschman index hhi to measure market concentration for purposes of antitrust enforcement. Lian yujun additional contact information lian yujun. The impact of competition on debt ratio of manufacturing. They discussed about hhi index which is usually used to evaluate the competitiveness of firms or industries. Hh and e containing the herfindahlhirschman and entropy.
Basic model, such as fixed effect and random effect were put in priority. To examine the effects of the racial composition of residents on nursing homes financial and quality performance. Therefore you must have just one value for this index to characterize a given market it does not vary across companies on this market. All you have to do is to figure out which of the billions packages available on cran ok. Divide the target companys total revenue by the entire industrys total market sales. The hhi is calculated by summing the square of each firms market share. One way to accomplish this is to use a generalized linear model glm with a logit link and the binomial family. Data were analyzed from november 19, 2016, through march 2, 2017. The herfindahlhirschman index hhi is a commonly accepted measure of market concentration. We can use the keep command to keep just these five variables.
This module shows the use of if with common stata commands. I would now like to calculate the hhi index based on these two columns. Oecd glossary of statistical terms herfindahl index definition. Apr 01, 2020 hello all, i am working on a panel data of 200 firms from 19952019. May 09, 2012 dear all, for my research i have to compute the hhi index measures concentration within industries for several industries over time my dates are quarterly observations. Hi, i am writing a thesis regarding export diversification in the region of west africa ecowas.
Where can i locate the concentration ratio and herfindahl. Using if with stata commands stata learning modules. Feb 19, 2020 the herfindahlhirschman index hhi for manufacturing industries only in the u. Sep 18, 2010 basically the herfindahl index is an indicator of the level of competition of a given market. This module should be installed from within stata by typing ssc install hhi. At 12 months women had significantly lower scores on the items 1, 3 and 6. How to calculate the herfindahlhirschman index hhi.
One can classify the competition structure of a market based on this ratio. Dear statalist, i have the following hypothetical trade dataset which contains imported items by importer. The herfindahlhirschman index hhi is calculated for the 50 largest companies manufacturing industries only. In 2008, the average medicaid hmo hhi index of florida was 0. The study examined medicare and medicaidcertified nursing homes across the united states that submitted medicare cost reports between the years 1999 and 2004 11,472 average per year. Stata module to generate herfindahlhirschman index hhi variables, statistical software components s458203, boston college department of economics. Library software open source custom projects index data. The association between hope, marital status, depression. The hhi is the sum of squared market share for all hospitals in each cities and counties, where market share is the number of a hospitals discharges divided by the total market area discharges. Nov 19, 2015 this feature is not available right now. The value of the index is the sum of the squares of the market shares of all firms in an industry.
Im trying to use if statements to assign correct labels for my graphs created inside foreach loop in stata. File indexing software for windows wincatalog 2019. Stata stata please help calculating herfinahl index. The herfindahlhirschman index hhi is a measure of the competition between firms and related industries. The result of this division equals your companys specific market share. Hausman test was use to find the right model for the real. Measures of hospital competition and their impact on early. How does one do regression when the dependent variable is. The hhi index is computed by summing the squared market shares for all companies within the same industry. Although i did not explain it during my lectures, calculating a gini index or displaying the lorenz curve can be done very easily with r. Stata module to generate herfindahlhirschman index. One advantage of using hhi over other possible measures of market concentration is its ability to reflect both the number of hospitals and the market shares across hospitals.
Similarly, y increased 50 percent between 2000 and 2001. Oecd glossary of statistical terms herfindahl index. This video gives a derivation of the lerner index and provides some sample problems. Aug 24, 20 this video gives a derivation of the lerner index and provides some sample problems. Weighing the effects of vertical integration versus market. The hhi is calculated by squaring the market share of each firm in the industry and summing the result. Lets make a table of rep78 by foreign to look at the repair histories of the foreign and domestic cars. Naturally, it would be nice to have the predicted values also fall between zero and one. Sun yatsen university, china statistical software components from boston college department of economics. Although the manufacturers often claim these packages build indexes, the actual results are a list of words and phrases, sometimes useful in the beginning stages of building an index. According to the, hhi is a strong index to assess the competitive capabilities by sectors and ranges from 0 to 1. The herfindahlhirschman index hhi is a widely used measure of market concentration. I need to construct a hhi index for ethnic diversity for each region in the survey and i have stata version 10.
Mar 16, 2015 the market concentration hhi is calculated by squaring the market share of each bankfirm competing in a market, and then summing the resulting numbers. Hospital competition and patientperceived quality of care. Herfindahl index i am trying to calculate degree of concentration in an industry by using the herfindahl index. Hello all, i am working on a panel data of 200 firms from 19952019. Hhi competition index herfindahlhirschman index has the opposite effect on debt ratio. The market concentration hhi is calculated by squaring the market share of each bankfirm competing in a market, and then summing the resulting numbers. Dear all, for my research i have to compute the hhi index measures concentration within industries for several industries over time my dates. File indexing software for windows wincatalog 2019 automatically index all files and folders from disks and find files quickly using advanced powerful search and search for duplicate files, without having to insert the original disk. Imf, 2004, compilation guide on financial soundness indicators, imf, washington dc, appendix vii, glossary. For this module, we will focus on the variables make, rep78, foreign, mpg, and price. When you use the commands i wrote you do end up with one observation corresponding to the index for your dataset.
The data, after had been collected, were input to the stata software for analysis. Our analysis used cities and counties as units of the health care market. This will allow me to get the herfindahlhirschman index by importer for each item. Regards, syed basher qatar national food security program for searches and help try. The association between managed care enrollments and.
You can do anything pretty easily with r, for instance, calculate concentration indexes such as the gini index or display the lorenz curve dedicated to my students although i did not explain it during my lectures, calculating a gini index or displaying the lorenz curve can be done very easily with r. At fixedradius approach with distances from 100 to 150 km, competition in cabg was. Development of competition indicators in the norwegian. Jan 20, 2020 divide the target companys total revenue by the entire industrys total market sales. Stata module to compute herfindahl index, statistical software components s457512, boston college department of economics, revised 30 aug 2012. The full dataset with all 284 variables documentation hdi. How to calculate the herfindahlhirschman index hhi the herfindahlhirschman index hhi is a measure of the competition between firms and related industries. If the software is correctly installed on your computer clicking the link above starts up the software and opens the data file and you can start your analyses. Market competition was measured using the herfindahlhirschman index hhi.