There are demand and supply functions given. A question on causal inference, problems of omitted variable bias and measurement error. see below please. the first parts task is to interpret, and the second part is to explain the effect of adding another variable.

Consider the following simultaneous, two equation model of demand and supply in an agricultural market. Demand Function: Q? = do + a1P; + azle + uit (1) Supply Function: Qt = Bo + B1Pt + u2t (2) where Q? is the quantity demanded, Q; is the quantity supplied, Pt is price, It is consumer income, and can be considered as predetermined or 'exogenous'. The terms uit and uzt are the error terms for each equation. (a) What is the best way to interpret the data on prices and quantities we observe for data based on this system? Does the observed data reflect information on a single set of demand and supply curves? Draw diagrams to illustrate your answer. (4 marks) (b) Next, suppose we added another variable, wealth R , to the demand equation. What implication does this have for our attempt to identify the supply equation? (6 marks)