Market prices may move up or down (or remain the same)in response to a host of factors causing shifts in supply (the whole supply curve) or demand (the whole demand curve) or both together. Bad weather makes prices go up--not just the prices of agricultural products, but of a great many other goods ranging from steel to nightgowns--because of interruptions in production, breakdowns in transportation, power failures, etc. Changes in technology cause shifts in supply curves a more efficient way of making transistors bring down the prices of calculators, computers, radios, television sets, record players, recorders. Increases in the scale of production, as we have seen, often bring down certain production prices. Shrinking. oil and mineral reserves contract supply, and prices move up. 'Diseconomies' resulting from shrinking scales of production, as when the market for handmade pocket books, horse-drawn carriage, grandfather clocks, custom tailoring, and handmade furniture contracts, push up the price of such products not only absolutely, but relatively far above what they were in the old days, when skilled labor was cheaper and more abundant. With which of the following topics is the author primarily concerned?