1.Abstract2.引言3. THEORETICAL BACKGROUND AND HYPOTHESES3.1Scientific Norms in Context3.2Social Exchange and Sharing in Academia3.3Impact of Academic Entrepreneurship3.4Shift in Sharing Forms3.5Overall Transactions3.6The Science Community in Japan4.DATA AND METHODS4.1Sample and Data4.2Measures5.RESULTS5.1Description of Material Transfer Transactions and Entrepreneurial Activities5.2Impact of Academic Entrepreneurship5.3Alternative Explanations6. DISCUSSION AND CONCLUSIONS