9. 1.1 Say's law Jean baptiste Say( 1767-1832)is a French economist Supply creates its own demand. That means the economy could never suffer from underemployment or succumb to Thomas' fear of under-consumption. Total spending(demand) would always be sufficient to justify production at full employment(supply)9.1.1 Say’s law Jean Baptiste Say (1767-1832) is a French economist. “Supply creates its o s its own demand.” That means the economy could never suffer from underemployment or succumb to Thomas’ fear of under-consumption. Total spending (demand) would always be sufficient to justify production at full employment(supply)