About the Data

The stock data used in this chapter come from the Cens

for Research in Security Prices $($CRSP$)$ by way of Whar$-$

ton Research Data Services. Analysts at CRSP carefully

adjust their data for accounting adjustments such as

dividend payments and stock splits.

Questions for Thought

These questions consider stock in Pfirer, the pharmaceut

cal manufactures. The data are monthly and span $1944$

through November $2015.$

The timeplot in Figure $9$ shows the price at the

end of the month of one share of stock in Pfizer.