This report revises and simplifies the extra-value approach (developed previously in Research Report 166) for member-producers to evaluate their cooperative's performance. Extra value is defined as net savings after subtracting an interest charge on equity. For comparisons over time and among cooperatives, extra value is expressed as a percentage of operating capital to generate a scale-neutral and mode-neutral, extra-value index for each cooperative or group of cooperatives. The extra-value approach is also used to examine the performance of the surviving cooperatives following mergers and consolidations. The influence of cooperative size on performance is also examined.