Medical Liability Insurance Premia: 1990–2016 Dataset, with Literature Review and Summary Information

• Author: Sonal Vats,Jeffrey Traczynski,Victoria Udalova,Bernard Black,Jeanette W. Chung
• DOI: http://doi.org/10.1111/jels.12146
• Date: 01 March 2017
• Published date: 01 March 2017

Medical Liability Insurance Premia:

1990–2016 Dataset, with Literature Review

and Summary Information

Bernard Black,* Jeanette W. Chung, Jeffrey Traczynski, Victoria Udalova,

and Sonal Vats

This document and the accompanying dataset provide six things: (1) a dataset covering 27

years (1990--2016) of medical malpractice (med mal) insurance premia, compiled with

extensive data cleaning from the only available source for these rates, annual surveys

conducted by Medical Liability Monitor (MLM); (2) an accompanying codebook; (3) the

Stata code we use to clean the raw data; (4) merger of the MLM data with related datasets

from the National Association of Insurance Commissioners and the American Medical

Association; (5) a survey of prior uses of the MLM data; and (6) a summary analysis of the

data. We hope that the availability of this cleaned dataset will prompt further research on

the effects of med mal premiums on provider behavior. We plan, but do not promise, to

update the dataset as additional annual releases become available. The dataset, codebook,

and code are available on SSRN at http://ssrn.com/abstract52716911.

I. Introduction

This article describes, and the accompanying dataset contain, rate information for medi-

cal malpractice (med mal) liability insurance over 1990–2016. The original data source

is annual surveys conducted by Medical Liability Monitor (MLM), which MLM provides to

researchers in paper form. The raw data have important weaknesses, especially in the

earlier years, which we discuss below. They are nonetheless valuable because MLM is the

only national, longitudinal source of data on med mal insurance rates. We conduct

extensive cleaning of the raw data and provide both raw and cleaned datasets, together

with the Stata code we use to go from raw to cleaned data. We document the cleaning

*Black is the Nicholas D. Chabraja Professor at Northwestern University, Pritzker School of Law, Institute for

Policy Research, and Kellogg School of Management; Chung is Research Assistant Professor of Surgery (Surgical

Oncology) at Northwestern University Feinberg School of Medicine; Traczynski is Assistant Professor of

Economics at the University of Hawaii at Manoa; Udalova is Economist at the Center for Administrative Records

Research and Applications at the U.S. Census Bureau; Vats is a Postdoctoral Fellow at Northwestern University,

Kellogg School of Management. Address correspondence to Bernard Black, email: bblack@northwestern.edu.

We thank Michael Matray, editor of Medical Liability Monitor, for assistance in this process, and for his willing-

ness to allow us to provide the MLM data in this form; Eric Sun for providing his coding of the MLM data for

1991–2003, and Mohamed Rahmati for assistance in compiling the dataset.

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Volume 14, Issue 1, 238–254, March 2017

steps in the Stata code and in the accompanying online codebook and Appendix, avail-

able on SSRN. We provide the datasets “as is.” We are not liable for coding or other

errors.

We link the MLM data with several related datasets: county rural-urban codes

(from 2013); annual county- and state-level data on population (from the Census

Bureau); number of total and active, nonfederal physicians, with a breakdown by special-

ty (from the Area Health Resource File, originally from the American Medical Associa-

tion); annual state-level data on paid med mal claims against physicians from the

National Practitioner Data Bank (NPDB), available through 2015; and data on direct

premiums written by med mal insurers from the National Association of Insurance Com-

missioners (NAIC), available through 2015. We also provide a literature review of papers

using the MLM data and summary information on the association between med mal

insurance premia and other relevant features of the med mal landscape.

We prepared this “Med Mal Insurance Dataset” in part for our own use and in

part to provide a standard source for med mal insurance rates and related data, which

can assist other researchers. We plan, but do not promise, to update the data as addi-

tional years become available. Please advise us of any errors or suggestions for improve-

ment. Please cite this article in the usual way. Please cite the dataset separately as

Bernard Black, Jeanette W. Chung, Jeffrey Traczynski, Victoria Udalova, and Sonal Vats,

Medical Malpractice Liability Insurance Dataset (1990–yyyy) (where yyyy is the latest data

year, currently 2016), at http://ssrn.com/abstract52716911.

1

II. Dataset and Limitations

Beginning in 1991, MLM has conducted and published annual surveys of medical liabili-

ty insurance premia for physicians in three specialties: ob-gyn (OB), internal medicine

(IM), and general surgery (GS), generally in October, for rates effective as of July 1 of

the year of publication. Table 1 provides details on each annual report. MLM generally

reports rates in nominal dollars for “occurrence” policies with “standard” limits of $1M

per occurrence/$3M per calendar year. These standard limits have not changed since

inception of the survey. We use the 1991 data on percentage change in premia to

extend the data back to 1990.

A. MLM Dataset

The Med Mal Insurance Dataset includes a cleaned data file, MLM_1990_2016.dta, and nine

data processing files, MLM.do, MLM_RateAreaDefinitions.do, MLM_NAICCompanyCodes.do,

MLM_CleanCountyNames.do, MLM_FIPS_CountyCodes.do, MLM_FIPS_StateCodes.do,

1

To protect MLM’s interest in its own survey, we have agreed to publicly post a restricted dataset, which includes

other variables through the latest available year, but MLM data only through 2002. We can release the full dataset

to persons who purchase a subscription to MLM (current cost is $395). Instructions on how to subscribe to MLM

and obtain the full dataset are available at http://ssrn.com/abstract52716911.

239Medical Liability Insurance Premia