Effects of Implementing State Insurance Market Reform, 2011-2012. Statistical Testing


We conducted descriptive analyses to address the study research questions. T-tests were used to determine whether means were significantly different, and estimates of variance were corrected for using finite population correction. The paper presents national and state-wide results. We examine multi-year trends for dependent variables, and analyze variations in dependent variables by selected independent variables. Dependent variables are:

  1. Premium increases
  2. Percent of rate increases approved by state regulators
  3. Percent of premium rate increases modified by state regulators

We present findings separately for the individual insurance and small group markets. Key covariates are:

  1. State regulatory authority
    1. Prior approval
    2. File and use
    3. HMO review authority only
    4. Rate review authority
    5. No requirement for filing
  2. Product type (HMO, PPO/HDHP, indemnity)
  3. Carrier size (top three carrier in the state and market, other)
  4. Market concentration in the individual and small group markets
    1. High – Largest three carriers in state have 80 or more percent of the market
    2. Medium – Largest three carriers in state have 50-79 percent of the market
    3. Low – Largest three carriers in state have less than 50 percent of the market

For state-level estimates, we required filings to encompass a minimum proportion of 50 percent of NAICreported state-wide enrollment to report results for a given state and year to ensure reliability. Multivariate modeling is beyond the scope of this study.

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"20130607InsMktReformReportFnl.pdf" (pdf, 1.46Mb)

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