4. Consider the following demand equation system. Let Ybe total expenditure on comsumer durables, non-durables and services and (Ed, En, Es) be expenditures on the three categories, and (Pd, Pn, Ps) are prices of each category. As defined, Y= Ed+En+Es Ed En Es = = d+ dY+ ddPd+ dnPn+ dsPs + d n+ nY+ ndPd+ nnPn + = S nsPs+n + sY+ Y+ sdPd+ snPn + ssPs + Es Prove that + n + = 1, and four other d S estimates (,) sum to zero across equations,. i.e., for example, d+n+ s = 0 and 0 and dd + nd+ sd = 0, etc. (Hint: Use partitioned regression estimation method). Matlab code to read various types of data data load('c:\TEACHING\Econ60302\Homework\Hw1.1Data.txt'); data0=importdata('c:\Teaching \Econ60302\Homework\Table8.1.txt',' ',1); data=xlsread('c:\TEACHING\Econ60302\Homework\TableF2_2.xls');