A new model of economic growth introduces the knowledge filter between new generic knowledge and economically-useful knowledge. It identifies both the formation of new ventures and the absorptive capacity of incumbent firms as the mechanisms that penetrate the knowledge filter. Recent empirical work has shown that new firms are more proficient at penetrating the knowledge filter than are incumbent firms; however, the analysis has only examined expanding economies and has relied on purely cross-sectional regression methodologies. This study explores the role of new and incumbent firms in penetrating the knowledge filter utilizing recent developments in spatial panel estimation techniques to provide a more robust set of findings. The results suggest that new firms are more proficient at penetrating the knowledge filter in declining and growing regions alike.