Ken Erdedy owns 14 units of marijuana. He both consumes it and sells it; and the latter activity is his only source of income. His utility function is U(x,y) = x^4 * y^3, where x denotes the units of marijuana he consumes and y denotes the composite good, i.e. the dollars he spends on everything else. The market price of the marijuana changed recently from 6 to 12. What is the wealth effect of this price change (using Hicksian decomposition) on marijuana?