Cause and Effect

Economists often use graphs to advance an argument about how the economy works. In other words, they use graphs to argue about how one set of events causes another set of events. With a graphs like the demand curve, there is no doubt cause and effect. Because we are varying price and holding all other variables constant, we know that change in the price of novels cause change in the quantity Emma demands. Remember however that our demand curve came from a hypothetical example. When graphing data from the real world it is often more difficult to establish how one variable affects another.

The first problem is that it is difficult to hold everything else constant when measuring how one variable affects another. If we are not able to hold variables constant, we might decide that one variable on our graph is causing changes in the other variable when actually those change are caused by a third omitted variable not pictured on the graph. Even if we have identified the correct two variables to look at we might run into a second problem reverse causality. In other words, we might decide that A causes B when in fact B causes A. The omitted-variable and reveres-causality traps us to proceed with caution when using graph to draw conclusions causes and effects.

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RENT CONTROL IN THE SHORT RUN AND LONG RUN

One common example of a price ceiling is rent control. In many cities the local government places a ceiling on rents that landlords may charge their tenants. The goal of this policy is to help the poor by making housing more affordable. Economists often criticize rent control arguing that it is a highly inefficient way to help the poor raise their standard of living. One economists called rent control the best way to destroy city other than bombing. The adverse effects of rent control are less apparent to the general population because these effects occur over many years. In the short run landlords have a fixed number of apartments to rent and they cannot adjust this number quickly as market conditions change. Moreover the number of people searching for housing in a city may not be highly responsive to rents in the short run because people take time to adjust their housing arrangements. Therefore the short-run supply and demand for housing are relatively inelasti...

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CAN CONGRESS DISTRIBUTE THE BURDEN OF PAYROLL TAX

If you have ever received a paycheck you probably noticed that taxes were deducted from the amount you earned. One ot these taxes is called FICA an acronym for the Federal Insurance Contribution Act. The federal government uses the revenue from the FICA tax pay for Social Security and Medicare the income support and healthcare programs for the elderly. FICA is an example of a payroll tax which is a tax on the wages that firms pay their workers. In 2005 the total FICA tax for the typical worker was of earnings. Who do you think bears the burden of this payroll tax firms or workers. When Congress passed this legislation it tried to mandate a division of the tax burden. According to the law half of the tax is paid by firms and half is paid by workers. That is half of the tax is paid out of firms revenues and half is deducted from workers paychecks. The amount that shows up as a deduction on your pay stup is the worker contribution. Our analysis of tax incidenc...

The Variety of Demand Curves

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