Base rates are premium rates determined by an industry-wide classification rather than just one employer's work experience.
Therefore, base-rated employers' workers' compensation premium rates are set by industry-wide claims costs. This means if a type of work has high industry claims costs, such as construction, your premiums will be higher because the industry warrants it and not because of any record you have of filing claims.
Base-rated employers pay premiums based on the average costs of claims filed against all Ohio employers in like (or similar) industries who use the same NCCI manual classifications.
For more information, refer to Calculating rates and the NCCI manual classifications.