@article {637,
	title = {Threshold Externalities in Economic Development},
	journal = {The Quarterly Journal of Economics},
	volume = {105},
	year = {1990},
	month = {Jan-05-1990},
	pages = {501},
	issn = {00335533},
	doi = {10.2307/2937797},
	url = {http://qje.oxfordjournals.org/lookup/doi/10.2307/2937797},
	author = {Azariadis, Costas and Drazen, Allan}
}
