State the difference between Identifier variables and Response variables with the help of an example.

The market for corn in country a is highly competitive. at the current market price of $5/bushel there is a shortage of 100,000 bushels of corn in this country. media reports claim that the price of corn will rise drastically in the near future. according to these reports, the neighboring country b had witnessed a similar situation recently. at the same price, the shortage in country b was also 100,000 bushels and eventually the equilibrium price in b went up to $10/bushel. both countries are known to have equal number of corn producers and the market supply of corn is identical at all prices. this, combined with the fact that consumers in the two countries also have similar tastes and preferences, led the media to conclude that the price of corn in country a would soon be as high as $10/bushel. the new equilibrium price turns out to be below $10/bushel, what inferences can be drawn?

Suppose an economist believes that the price level in the economy is directly related to the money supply, or the amount of money circulating in the economy. the economist proposes the following relationship: p=a x m - p=price level - m=money supply - a=a composite of other factors, including real gdp, that change very slowly over time. how might an economist gather empirical data to test the proposed relationship between money and the price level? an economist would persuade the federal reserve to change the money supply to various levels, and observe the resulting changes in the price level. unlike researchers in the hard sciences, economists cannot study complex relationships using data. economists do not usually develop theoretical models of the economy but only analyze summary statistics about the current state of the economy. an economist would look for data on past changes in the money supply, and note the resulting changes in the price level

In macroeconomics, to study the aggregate means to study blank