Russian, a Jamaican, an American, and a Mexican

A Russian, a Jamaican, an American, and a Mexican were on a rafting expedition together. Midriver the Russian pulled out a HUGE bottle of Stolychnaya, took a swig, and threw it overboard.
"Hey, what the hell'd you do that for?" blurted the American.
"We have so much vodka in Soviet Union that we can afford to waste it." explained the Russian cherfully.
A few miles downstream the Jamaican took out a HUGE bag full of marijuana, rolled a giant joint, took a few puffs, and tossed it overboard.
"Jesus, that stuff's expensive," bellowed the American. "What'd you do that for?"
"In Jamaica, ganja grows everywhere, mon," said the Jamaican with a grin. "We can afford to waste it."
Thinking hard, the American settled back into his seat. A few miles downriver he stood up with a smile and threw the Mexican overboard.