With growing commercializa1ion of the national economy, agriculture and industry have become increasingly interdependent. The development has extended so far that the major problems found in agriculture now are those growing out of interdependence with other sectors of the national exchange economy. A slight swell in farm production, relative to employment and output in the rest of the economy, causes a rapid recession of farm income. A small decline in farm output, relative to employment in the national economy, causes farm prices to spiral upward. Then, too, it is known that depression or prosperity in agriculture is largely a function of the state ·of economic affairs in non-agricultural sectors of the national economy. While a few of these general qualitative interrelationships between agricultural and other sectors of the economy are known, knowledge of the exact quantitative inter-relationships is meager. More quantitative information of the economic inter-relationships will be important in the years ahead. The major and basic problems which face the agricultural sector of the national economy are in the realm of interdependence coefficients.