1. Aaron HJ (1990) Discussion of why is infrastructure important? In: Munnell AH (ed) Is there a shortfall in public capital investment? An overview. Conference series proceedings 34, Federal Reserve Bank of Boston, pp 51–63
2. Acemoglu D, Angrist J (2001) How large are human capital externalities? Evidence from compulsory schooling laws. In: Bernanke BS, Rogoff K (eds) NBER macroeconomics annual 2000. MIT Press, Cambridge MA, pp 9–58
3. Aschauer DA (1989) Is public expenditure productive? J Monet Econ 23:177–200
4. Aschauer DA (1997) Output and employment effects of public capital. Jerome Levy Economics Institute, Bard College
5. Audretsch D, Keilbach M (2004) Entrepreneurship capital and economic performance. Reg Stud 38:949–959