Final answer:
The value of αM in the linear demand function depends on the relationship between goods X and Y.
Step-by-step explanation:
In the linear demand function Qxd = α0 + αxPx + αyPy + αMM + αHH, the value of αM depends on the relationship between the goods X and Y. If X and Y are complements, then the value of αM would be positive. If good X is inferior, then the value of αM would be negative. If good X is normal, then the value of αM would be positive. And if X and Y are substitutes, then the value of αM would be negative.