Previous research found a positive relationship between concentration and total factor productivity in food manufacturing. On industry (i.e., meatpacking plants [SIC 2011]) was selected for independent analysis due to a relatively sharp increase in concentration in recent years. The methodology chosen was similar to previous studies. Total factor productivity increased 2.4 percent per year, and labor productivity increased 3.3 percent per year for meatpacking plants over the 1958-82 period. Concentration in meatpacking did not positively or negatively affect total factor productivity or labor productivity over the 25-year study period.