“…at the state-or country-level. These exploit panel data (Halvorsen, 1975;Azevedo et al, 2011;Maddala et al, 1997;Liu, 2004;Carlevaro and Spierer, 1983;Spierer, 1988;Labandeira et al, 2012;Filippini, 1999;Alberini and Filippini, 2011;Blázquez et al, 2013) or, alternatively, for country studies, just the time-series nature of the data (Prosser, 1985;Bentzen and Engsted, 1993;Fatai et al, 2003;Kamerschen and Porter, 2004;Holtedahl and Joutz, 2004;Narayan and Smyth, 2005;Ziramba, 2008;Amarawickrama and Hunt, 2008;Dergiades and Tsoulfidis, 2008;Sa'ad, 2009;Fan and Hyndman, 2011).…”