Mixed results from empirical studies concerning the effectiveness of Technology business incubators (TBI) raise questions of the role of local government as a legitimate sponsor of incubators. In response to the current debate on the role of government in incubator program, this study undertakes a comparative evaluation to assess the differences both in selection of inputs and in outcomes between public and private technology incubators. The primary question examined through this research is whether publicly funded technology business incubators could be substituted by private ones. Using case study methodology, this research studies exemplar incubators of different sponsorship types to observe roles of public engagement for different sponsorships. Using National Establishment Time Series (NETS) data base, this research then conducts two-group comparison to exam whether performances of TBIs differ by sponsorships, in terms of sales, wages and employment.