50. Income-tax: As regards the basis of distributing between provinces the share of proceeds from taxes on income, we are of the opinion that no single basis would lead to equitable results. Origin or locus of income is no doubt relevant, but in the complex industrial and commercial structure of modern times, where a single point of control often regulates a vast network of transactions, where the raw materials come from one place, are processed in another, manufactured in a third, marketed wholesale in a fourth and ultimately sold in retail over a large area, contracts are made at places different from where they are performed, money is paid in at one place and goods delivered at another and more than one of these stages relate to the same tax-payer, the assignment of a share of profits to each stage can only be empirical or arbitrary.