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Eventus |
GeneralSoftware CapabilitiesLong-horizon event study methods CUSIP to CRSP PERMNO conversion Tips, Tricks and TechniquesControl-firm event study approach Indexing data sets for the SASNONCRSP method Indexing data sets for the companion portfolio approach Basing the estimation period for one event on the date of a different event Holding a firm-specific estimation period constant across multiple event studies Retrieving index returns alone Retrieving returns a fixed number of trading days before a given calendar date Error Messages"Statement is not valid" errors on all Eventus statements Error messages from Extract statement with the BuyHold option Interpretation of ResultsMarket index with SP500 option isn't S&P 500 ... ? Meaning of Extract, OutWin or FileWin weights Output of RETURNS with SIZEINDX and BOTH options Compatibility with Other VendorsCompatibility with CRSP and how to handle updates of CRSP
"Statement is not valid" errors on all Eventus statements Q: We installed Eventus for Windows, but when we try to run a test program, the Eventus; statement and each subsequent statement is flagged with the messageERROR 180-322 Statement is not valid or is used out of proper order. Whats going on? Solution: This typically is the result of installing Eventus in one user account (often the special login named Administrator in Windows XP Professional), then trying to use it from another without further ado. If you go back to the same login used for installation and find that you can successfully run Eventus, then only a few simple manual steps are needed to make Eventus available to other user accounts on the same computer. To make Eventus available to another user on the same computer, please
close SAS and copy the
following files from the first user's My SAS Files
folder (typically something like My Documents\My SAS Files\9.1) to the next user's My SAS Files folder:
Another possibility is that the SAS 9.1 configuration file
arrangement was changed after SAS 9.1 was installed on the PC. To investigate
this possibility, close SAS and use Notepad to check all files SASV9.CFG on your
computer (use a desktop search tool such as those offered by Yahoo!, Google or
X1 to find them). Typically there are two, in C:\Program Files\SAS\SAS 9.1\ and
C:\Program Files\SAS\SAS 9.1\nls\en where en may be replaced by another
two-letter language code. One of the files contains over 200 lines including the
line A third possibility is that the user's My Documents file has moved since SAS was installed. A variant of this is a laptop on which My Documents is defined one way when the laptop is docked or attached to a network and another way at other times. My SAS Files is usually a folder under My Documents and so is affected by this Hogwarts staircase problem. In this situation, close SAS and copy the files listed above for the multiple user account situation, from the My SAS Files folder in which they currently appear to the My SAS Files folder under the new or undocked My SAS Files. Return to list of FAQ subjects Extract with BUYHOLD doesn't work Q. When I run the extract statement with the buyhold option, multiple error messages appear in the log window and the file of extracted returns is not created. The EvtStudy statement included buyhold.Solution: Upgrade to Eventus 8, where you don't have to worry about this. In fact, you might not even want to use Extract, which typically can be replaced by the new OUTWIN= option of the EvtStudy statement. If you do run into this problem while using Eventus 7, on the EvtStudy statement that creates the data set to be extracted from, include the option package=defgp. Return to list of FAQ subjectsImplementing a control-firm approach Q: How can I use a control-firm approach, where each sample firm is pre-matched to a similar firm? Solution: The control-firm approach as it commonly appears in the literature can be implemented using the SHORT and GROUP options on the REQUEST statement. Include the PERMNOs (or whatever security identifier is being used) for both the sample and control firms in the same request file™. Include a grouping variable which has a unique value for each sample firm; each control firm should receive the same grouping variable value as its matched sample firm. See the documentation for the REQUEST statement option GROUP for details. Also include a short-long indicator, 'S' for control firms and 'L' for sample firms. See the documentation of the REQUEST statement option SHORT for details. The simple paired difference test frequently used with the control-firm approach can be invoked with the EvtStudy statement option CSECTERR. To suppress benchmark models, include the EvtStudy statement options RAW NOMM NOMAR. An estimation period still must be defined, but may be forced to overlap the event period using the EvtStudy statement option OVERLAP and appropriate specifications of the REQUEST statement options ESTand ESTLEN. Return to list of FAQ subjects Data set indexes for SASNONCRSP Q: Could you explain further how the data statement index options needed for SASNONCRSP work? Solution: Indexing allows a SAS data set to be used (by Eventus in this case) as if the data set were sorted by the index variable or variables. In Eventus 8, you no longer need to index the mini-database component data sets; Eventus builds the indexes for you automatically. Return to list of FAQ subjects Q: Could you explain how to index the portfolio assignment data set for the companion portfolio method? Solution: In the code below, replace mydataset by
the name of the data to which the PORT1DS option will point. If you are
preparing the data set for a SASNONCRSP run, also change permno to the variable
name of your security identifier. Return to list of FAQ subjects Same estimation period for different events Q: I want to run separate event studies on three different events using the same sample of firms (three events per firm, with a different event date for each firm). I want the estimation period to end 31 days before the first event date. I read about the est=specific option in the User's Guide. But exactly how do I use it, and how can I find out the estimation period ending date for the first event?Solution: Run Eventus statements like the following. * Convert calendar event date to CRSP trading day number; Eventus; DateConv outsas=work.temp1; * Move date back 31 trading days; Eventus; DateConv insas=work.temp1 datefmt=crsp shift1=-31 outsas=work.temp2; * Combine shifted and original dates into a new request file in SAS data set form; data request_event1; merge temp1 temp2(rename=(eventdat=estend)); by permno; run; * Print the request file for visual inspection; proc print data=request_event1; id permno; format eventdat estend yymmddn8.; run; * Use the new request file to run the first event study; Eventus; Request insas=work.request_event1 est=specific; EvtStudy; * Set up the request file for the second event study; filename request 'C:\My Request Files\File Name 2.txt'; Eventus; DateConv outsas=work.temp3; data request_event2; merge temp3 temp2(rename=(eventdat=estend)); by permno; run; * Run the second event study; Eventus; Request insas=work.request_event2 est=specific; EvtStudy; Further event studies can be run using the same estimation period for each firm as in the first event study using a request file™ setup process similar to that shown for the second event study above. Any shift is calculated in terms of the input date units. When datefmt=crsp appears on the DateConv or Request statement, any shift1 or shift2 option on the same statement produces a shift of the specified number of trading days. Without datefmt=crsp, the shift is performed for the specified number of calendar days. If you have options on the event study Request statement that further describe the request file™ contents, such as ID=... or CUSIPERM, the same options can be used on DateConv too. If using CUSIPERM or if there is more than one event with the same PERMNO, the use of ID=, and merging by the specified identifying variable instead of PERMNO, are recommended Item revised 11 February 2004. Return to list of FAQ subjects Basing the estimation period for one event on the date of a different event Q: Is there a way to set up the estimation period, for an event study around one event , relative to the date of a second event? Solution: Yes. The Eventus statements below demonstrate how to set up the estimation period for a security offer registration as days +31,+150 relative to the actual offering date. The request file™ contains the following lines, where the four fields are CUSIP, registration date, offering date and user-defined event ID number: 38141G10 20011127
20020107 2 * Use the TWIN option and Dateconv statement to convert both dates
(registration and offering) to CRSP trading day numbers; Eventus twin; DateConv cusiperm outsas=work.temp1 id=id; * Use the TWIN option and Dateconv statement to read both dates and shift the second 150 trading days into the future, to create an estimation-period ending date of offering date+150; Eventus twin; DateConv insas=work.temp1 datefmt=crsp shift2=+150 outsas=work.request id=id; * Rename the
CRSP-date variables to the required column names for a single
event date and specific estimation period ending date; *
Run the event study, using datefmt=crsp to use crspday as the event date, est=specific
to use crspest as the last trading day of the estimation period (both specified
as CRSP dates) and estlen=120 to specify a 120 trading day long estimation
period; title 'Registration Date -- Estimation Period is Offering Date(+31,+150) Request insas=work.request datefmt=crsp est=specific estlen=120 id=id; EvtStudy; Item created 11 February 2004. Return to list of FAQ subjects Retrieving index returns alone Q: Is it possible to get returns for a market index alone? Solution: Run a program like the following. It also will retrieve returns for Adams Express stock, but because Adams Express has been active every day and month of the CRSP database (so far), no calendar range will be excluded due to non-listing. data request;permno= 10065; /* Adams Express */eventda1= '01JAN1926'D; /* Starting date here */eventda2= '01DEC2001'D; /* Ending date here */ output;stop; run ;
Eventus getdata monthly; /* remove monthly if daily wanted */ Request autodate insas=work.request;Returns index value outsas=work.indexdata; /* Note: CRSP value-weighted index will be variable Market in output SAS data set indexdata*/ Return to list of FAQ subjects Retrieving returns a fixed number of trading days before a given calendar date Q: I want to use the returns statement to extract, from the CRSP daily stock database, the return 31 trading days before a date that varies from firm to firm. I have the dates in an ascii text request file named c:\myproject\request.dat, where each line contains the PERMNO and calendar date for one firm (for example, 12345 19980701). If I use the shift1=-31 option on the Request statement, I get the return 31 calendar days before the given date, as the User's Guide states. But I need to shift back an exact number of trading days, not calendar days. How can I do this?Solution: Run Eventus statements like the following. The statements first produce a SAS data set format request file™ containing the specified event date in CRSP trading day number format, which is then used with the the shift1=-31 option on the Request statement to move back 31 trading days.
Return to list of FAQ subjects Q: Where can I obtain Fama-French factor data for event study purposes? Solution: Eventus for WRDS users can access the factor data, maintained by WRDS staff, through the SAS library name FF. Eventus 8.0 and greater for Windows users, please go to the Windows Start Menu folder for Eventus and select Fama-French Factor Installer, which downloads the factor data from Professor Ken French's web site and installs it in the SAS data set format expected by Eventus software. If your organization is an annual subscriber to Eventus and you have trouble obtaining the factors by the above methods or use Eventus for Solaris or Linux on your own organization's system, please our data sets page for other options. Return to list of FAQ subjects Q: How can I get Eventus software to put the stock return variance in a SAS data set? I am not interested in event study results, just the return variance. Solution: The following program creates a temporary SAS data set, work.volatile, that contains the variable OWNVAR, the variance of raw stock returns. It is assumed that the request file™ (read by the Request statement) contains the PERMNO of each stock and a stock-specific date that marks the end of the 253-day period for which you want the variance, and your own four-digit identifying number that you call "Item" for your security-events.
Return to list of FAQ subjects Standard errors of market model alpha and beta Q: How can I get the standard error of market model alpha and beta (as regression coefficients) from the estimation period for each security-event in an event study? Solution: The following program illustrates the
addition of the OutSAS option to the
Return to list of FAQ subjects SP500 option doesn't retrieve S&P 500 returnQ. When I specify the SP500 option, I still get the default market index. Why? Solution: As stated in the User's Guide, the SP500 option causes the Standard & Poor's 500 return from the CRSP stock database to replace the value-weighted index. This implies that to actually get the S&P 500, it is necessary to invoke the value-weighted index by using the VALUE option or BOTH option, for example:
Eventus getdata; Return to list of FAQ subjects Meaning of Extract, OutWin or FileWin weights Q. The weights produced by the OutWin or FileWin option of the EvtStudy statement, or by the Extract statement, look strange. How can I make sense out of them? Solution: The weights created by OutWin, FileWin and Extract are designed to meet the requirements of the WEIGHT statement in SAS regression procedure PROC REG, to simplify weighted least squares (WLS) cross-sectional regressions. The weights are designed to make the WLS estimation conform to the same assumptions about the variance as are used in the development of the Patell and Standardized Cross-Sectional tests. The weights may seem strangely proportioned because a) they are not intended to be portfolio weights, and do not sum to 1; and b) they are reciprocals of variance, not standard deviation, because that is appropriate for the way that PROC REG works, given the desired variance assumptions. Nevertheless, the weighting scheme is consistent with portfolio weights based on
the reciprocals of standard deviations. The following experiment demonstrates that this is
so. When the SERIAL and STDCSECT options are not specified on the
EvtStudy statement, the precision-weighted
cumulative average abnormal return printed in the default event study output is equivalent
to taking a weighted-average CAR using the square roots of the OutWin, FileWin or Extract weights. Run an event study using the OutWin=work.demo
option, but not the SERIAL and STDCSECT options. Then run the following statements: Return to list of FAQ subjects Output of RETURNS with SIZEINDX and BOTH options Q. When I run Eventus using the GETDATA option on EVENTUS statement, the SIZEINDX option on the REQUEST statement, and the option BOTH on the RETURNS statement, I get two sets of index returns, labeled EQUAL and VALUE. Do I assume that these are the value-weighted and equal-weighted indices for the size-decile index? Solution: No. Keep in mind that Eventus itself does not calculate the index returns, it just reads them from the CRSPINDX and SIZEINDX files. The returns in the SIZEINDX file are whatever they are, equal- or value-weighted. Traditionally the CRSP indices/decile product included only equal-weight size decile portfolios, and that is also what the size-index maker included in the Eventus installation kit produces. When using SIZEINDX on the REQUEST statement with the statement RETURNS INDEX BOTH; the
output contains: Return to list of FAQ subjects Compatibility with CRSP and how to handle updates of CRSP Q: Is Eventus® software compatible with the current CRSP U.S. stock database? Should we install the X-cut or the Z-cut of the CRSP data? Answer: Eventus 8.0 can directly read any recent release of the CRSP U.S. Stock Database if installed on the same computer as Eventus or accessible on a local network drive. Eventus 8.0 is compatible with both the X-cut and Z-cut and automatically detects which one is being used. Q: CRSP was recently updated on our local network, but unless I use the dbfnstmt option of the Eventus statement, Eventus for Windows still uses the previous version of the CRSP data. Answer: Except when the dbfnstmt option is present, Eventus uses the Windows environment variables CRSP_DSTK and CRSP_MSTK to locate the CRSP daily and monthly databases respectively. The dbfnstmt option bypasses the environment variables. When a CRSP update is installed, the environment variables are updated automatically on the PC or server on which the update is performed. Individual PCs accessing CRSP on a network drive need to have their environment variables updated manually. The environment variables are simple text strings containing the folder locations of the daily and monthly databases. Here is how to get to a screen where you can enter the new folder locations. If you have a Windows Start menu folder named CRSPAccess, try CRSP Client Environment. Otherwise, open My Computer using the corresponding desktop or Start menu icon, click on View System Information, go to the Advanced tab, and click the Environment Variables button. These steps are for XP; Vista may be a little different. Return to list of FAQ subjects Compatibility with Thomson Financial Datastream Q: Can Eventus® software use Datastream data? Answer: Yes, users have two options for doing this. One is to manually download the needed Datastream data and format it according to Eventus requirements for non-CRSP event studies, as described in the User's Guide. Another option is to use our EventStream software in conjunction with Eventus. Return to list of FAQ subjects Compatibility with versions of The SAS® System Q: With which versions of SAS does Eventus software work? Answer: Eventus 8.0 requires SAS 9.1 or 9.2. We currently recommend using either SAS 9.2 or SAS 9.1.3 Service Pack 4 and the current Base SAS hotfix bundle. FAQ last updated 19 June 2008. |
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