
	Where results make sense

Topic: Dummy variable

Related Topics

Gaussian function

Clairvaux Abbey

Residue theorem

Railroad buff

Eyrir

DMCRA

Uralla

Lila

Reydon

1456

V220

Food writing

	NationMaster - Encyclopedia: Free variables
		Variables bound at the top level of a program are technically free variables within the terms to which they are bound but are often treated specially because they can be compiled as fixed addresses.
		Variables are useful in mathematics and computer programming because they allow instructions to be specified in a general way.
		Usually, a variable is set to reside in some scope in program code, and entrance and leave of the scope coincides with the beginning and ending of a variable life, respectively.
	www.nationmaster.com /encyclopedia/Free-variables (1049 words)

	Spartanburg SC \| GoUpstate.com \| Spartanburg Herald-Journal (Site not responding. Last check: 2007-08-19)
		In regression analysis, a dummy variable (also known as indicator or bound variables) is one that takes the values 0 or 1 to indicate the absence or presence of some categorical effect that may be expected to shift the outcome.
		For example, in econometric time series analysis, dummy variables may be used to indicate the occurrence of wars, or major strikes.
		If all the dummy variables are included, their sum is equal to the constant term, resulting in perfect multicollinearity.
	www.goupstate.com /apps/pbcs.dll/section?category=NEWS&template=wiki&text=Dummy_variable (166 words)

	[No title] (Site not responding. Last check: 2007-08-19)
		Dummy coding a variable creates a set of indicator variables to represet the information in a categorical variable.
		Often analysts will use such a variable in a regression to capture the average (of the dependent variable) among those for whom a predictor variable is not available.
		Otherwise, the dummy variables are all missing when the original variable is missing.
	am.air.org /help/NAEPTextbook/AMHelp/AMHelpDummyCode.htm (194 words)

	DUMMY
		Since the number of dummies created is usually equal to the number of unique values taken by the input series, care should be taken that the series used has a limited number of values.
		When a "continuous" rather than "discrete" variable is used for input, the number of dummies created could be equal to the number of observations, and storage allocation problems are likely to be the result.
		The set of dummy variables is stored in data storage, and the listname (if one was specified) is defined as the variable names for the set of dummies.
	www.tspintl.com /products/tsphelp/dummy.htm (431 words)

	Dummy variable - Wikipedia, the free encyclopedia
		In regression analysis, a dummy variable (also known as indicator or bound variables) is one that takes the values 0 or 1 to indicate the absence or presence of some categorical effect that may be expected to shift the outcome.
		For example, in econometric time series analysis, dummy variables may be used to indicate the occurrence of wars, or major strikes.
		If all the dummy variables are included, their sum is equal to the constant term, resulting in perfect multicollinearity.
	en.wikipedia.org /wiki/Dummy_variable (195 words)

	Dummy Variables
		A dummy variable is a numerical variable used in regression analysis to represent subgroups of the sample in your study.
		In the simplest case, we would use a 0,1 dummy variable where a person is given a value of 0 if they are in the control group or a 1 if they are in the treated group.
		Another advantage of a 0,1 dummy-coded variable is that even though it is a nominal-level variable you can treat it statistically like an interval-level variable (if this made no sense to you, you probably should refresh your memory on levels of measurement).
	www.socialresearchmethods.net /kb/dummyvar.php (569 words)

	Methods & Measurements: Dummy Variables
		A dummy variable is a numerical variable used in regression analysis to represent subgroups of respondents in your sample.
		In the simplest case, we would code a dummy variable 0 and 1, where a person is given a value of 1 if they are in the group we wish to examine and a 0 if they are in the reference group.
		Dummy variables are useful because they enable us to use a single regression equation to represent multiple groups rather than writing separate equation models for each subgroup.
	colfa.utsa.edu /Sociology/MASTERS/dummyvars.htm (415 words)

	Dummy Variables (Site not responding. Last check: 2007-08-19)
		Dummy variables are very useful for capturing a variety of qualitative effects.
		Dummy variables that measure individual attributes may be coded in the data file and these can be assigned variable names and loaded into SHAZAM with the
		The dummy variable is now created and the OLS estimation is then run over the entire sample period of the data.
	www.umanitoba.ca /campus/acn/unix/software/vendor_html/shazam/dummy.htm (423 words)

	PA 765: Multiple Regression
		In this case the F-test of the significance of the interaction of the two variables is the significance of the change of R-square of the equation with the interaction terms and the equation without the set of terms associated with the ordinal variable.
		Thus for the set of dummy variables for "Region," assuming "North" is the reference category and education level is the dependent, a b of -1.5 for the dummy "South" means that the expected education level for the South is 1.5 years less than the average of "North" respondents.
		The variance of the residuals is the estimate of error variance, assuming all relevant variables are in the equation and all irrelevant variables are omitted.
	www2.chass.ncsu.edu /garson/pa765/regress.htm (19068 words)

	Multivariate Statistics - Categorical Variables
		Number of Dummy Variables: The number dummy coded variables necessary to represent a single categorical variable is equal to the number of degrees of freedom available for the categories.
		Keeping these general rules/guidelines for dummy variables in mind, a number of different coding schemes can be utilized depending on what type of relationship between the groups is of interest.
		The dummy and effect codes are easy to generate; they do not, however, produce orthogonal dummy variables which requires both the sums and the sums of cross products of the weights to be zero.
	www.uwsp.edu /psych/cw/statmanual/mrcategorical.html (1133 words)

	Appendix 4: Reduced form equations for fertility
		Estimates on the non-income variables are not greatly affected by treating expenditures as endogenous.
		The Punjab province is the excluded provincial dummy variable, hence the results indicate that women in the Sindh region have slightly lower fertility, and those in the NWFP have slightly higher fertility than in the Punjab region.
		Notes: (†) indicates variables for which parameter estimates reported in birth in the past 5 years model are for change in the variable from 0 to 1.
	www.worldbank.org /html/prddr/prdhome/peg/wps02/indexp9.htm (777 words)

	Home
		One way of approaching this for a given variable, X, is to create a dummy variable for X, where a score of 1 is assigned to cases with missing data and a score of 0 is assigned to cases with non-missing data.
		For example, if the missing data dummy variable is significantly correlated with gender, then this suggests that the data are not missing at random and that males are more or less likely to have missing data than females.
		The program 'Variable List' in ZumaStat gives you a list of the variables in the data file that can be shown in either alphabetical order or in the order they appear in the file, with or without labels and you can move between these formats with a simple click of the button.
	www.zumastat.com /SpssInterface.htm (2474 words)

	15 FUNCTIONS AND SUBROUTINES
		A dummy procedure is a dummy argument that is identified as a procedure (18.2.11).
		Each variable reference may be either a reference to a dummy argument of the statement function or a reference to a variable that appears within the same program unit as the statement function statement.
		A character dummy argument whose length specification is an asterisk in parentheses must not appear as an operand for concatenation, except in a character assignment statement (10.4).
	www.fortran.com /F77_std/rjcnf-15.html (7680 words)

	[No title]
		When the original variable is missing, all dummy variables will be missing (V7+ only).
		Otherwise, the dummy variables are named by appending numbers, 1, 2,...
		Variables using the format option must be listed first in the VAR= list.
	euclid.psych.yorku.ca /ftp/sas/vcd/macros/dummy.sas (615 words)

	BTS \| Chapter 3 - Pre- and Post-9/11 Econometric Analysis of Travel by Mode
		The exponential weights for the dummy variable used in the VMT equation for the 5-month period from September 2001 to January 2002 are: 1.000, 0.6494, 0.4217, 0.2738, and 0.1778.
		The exponential form of the dummy variable was found to be statistically significant, but the (0,1) dummy was not statistically significant.
		Given that the 9/11 dummy variables are statistically significant, it can be concluded that the negative effect of 9/11 on travel declines in a more arithmetic fashion for air travel over a 6 month period, in which there is a decline in the intercept.
	www.bts.gov /publications/estimated_impacts_of_9_11_on_us_travel/html/chapter_03/index.html (1585 words)

	Visualizing Categorical Data: dummy - Macro to create dummy variables
		, the dummy variables are named by appending the value of the VAR= variable to the prefix.
		Otherwise, the dummy variables are named by appending numbers, 1, 2,...
		Indicates the level of the baseline category, which is given values of 0 on all the dummy variables.
	www.math.yorku.ca /SCS/vcd/dummy.html (283 words)

	FAQ: Creating dummy variables
		A dummy variable is a variable that takes on the values 1 and 0; 1 means something is true (such as age < 25, sex is male, or in the category "very much").
		Dummy variables are also called indicator variables by some people.
		There are three ways to create dummy variables: one is to use generate, which creates one dummy variable at a time, another is to use tabulate, which creates whole sets of dummies at once, and the third is to use xi, which may allow you to avoid the issue of dummy-creation altogether.
	www.stata.com /support/faqs/data/dummy.html (613 words)

	How Increased Competition from Generic Drugs Has Affected Prices and Returns in the Pharmaceutical Industry
		The variable explaining brand-name competition is defined at the level of a drug's five-digit therapeutic class, as established by the Uniform Standard of Classification codes (see Box 3 in Chapter 3).
		That variable resembles imperfect competition based on a Cournot model, in which the equilibrium price is a function of 1/(N+1), N being the number of manufacturers.
		The variables explaining generic competition are GENDUM (a dummy variable) and INVNMG (the inverse of the number of generic manufacturers).
	www.cbo.gov /showdoc.cfm?index=655&sequence=7 (2538 words)

	dummy variable
		A variable that appears in a calculation only as a placeholder and which disappears completely in the final result is called a dummy variable.it usually takes on the values 0 and 1 (in statistics), and so can be called a binary variable too.
		In integration we use dummy variables.you know, the variables that are integrated out at the end of the problem.
		You see free variables in elementary math a lot in contexts like f(x)=x^2, in which x appears to be free.
	www.physicsforums.com /showthread.php?p=831074 (535 words)

	Multilevel - DUMMY Command (Site not responding. Last check: 2007-08-19)
		The DUMMY statement is used to create dummy variables for a selected variable.
		Names for the dummy variables are denoted by dummy1, dummy2, …, dummyk, where k equals the number of distinct values of the selected variable.
		The user can change the default names of the dummy variables by the inclusion of the PREFIX keyword in the DUMMY= command.
	www.ssicentral.com /lisrel/WebHelp/Syntax/Multilevel/DUMMY_Command.htm (110 words)

	Statistics 5102 (Geyer, Spring 2007) Examples: Regression with Dummy Variables
		for this variable (that is 1 when the individual is in the red category and 0 otherwise) and similar notation for the other categories.
		The reason is that when there are several categorical predictor we must drop one dummy variable from each set of categories and add one intercept to get a well-defined model.
		Having all the dummy variables would give a model with non-invertible X'X matrix, because the sum of all the dummy variables is the constant predictor, for example,
	www.stat.umn.edu /geyer/5102/examp/dummy.html (1089 words)

	The Mathematica Book Online: Principles of Mathematica \| Modularity and the Naming of Things
		Integration variables are a common example of dummy variables in mathematics.
		This variable is essentially "local" to the integral, and its name, while arbitrary, must not conflict with any other names in your mathematical expression.
		In many cases, the most important issue is that dummy variables should be kept local, and should not interfere with other variables in your mathematical expression.
	documents.wolfram.com /mathematica/book/section-2.7.5 (461 words)

	dummy
		By default, gnuplot assumes that the independent variable for the plot command is x, and the independent variables for the splot command are x and y.
		They are called the dummy variables because it is just a notation to indicate the independent variables.
		The set parametric command also changes the dummy variables (to t for plot and u,v for splot).
	www.phy.uct.ac.za /courses/gnuplot/dummy.html (97 words)

	TSP Interpretations (Site not responding. Last check: 2007-08-19)
		If we use the dummy race command this means that we now have a variable called race1 which has a value of 1 when the observation is white and a value of 0 otherwise.
		Because the coefficient on the married dummy is insignificant.
		For example, to test the null hypothesis that none of the dummy variables mattered in the determination of wages, we would first run an unrestricted regression in which all of the variables are included.
	www.eco.utexas.edu /Help/Handouts/tsptx.html (4367 words)

	Dummy - Wikipedia, the free encyclopedia
		A crash test dummy, a full-scale replica of a human being, weighted and articulated to simulate the behavior of a human body in an accident.
		Dummy reversal, technique in contact bridge to draw the opponents' remaining trump cards.
		Dummy file, files used to fit the space in data optical discs.
	en.wikipedia.org /wiki/Dummy (253 words)

	5 ARRAYS AND SUBSTRINGS
		If the symbolic name of a constant or variable that appears in a dimension bound expression is not of default implied integer type (4.1.2), it must be specified as integer by an IMPLICIT statement or a type-statement prior to its appearance in a dimension bound expression.
		A dummy array declarator may be either a constant array declarator, an adjustable array declarator, or an assumed-size array declarator.
		The values of those dummy arguments or variables in common, together with any constants and symbolic names of constants appearing in the dimension bound expression, determine the size of the corresponding adjustable dimension for the execution of the subprogram.
	www.fortran.com /F77_std/rjcnf-5.html (2315 words)

	POWERMUTT: Regression Analysis
		In an unstandardized regression equation in which the dependent variable is a “feeling thermometer” for Hillary Clinton, a “b” coefficient of 8.106 associated with gender would mean that, all else being equal, women rate her a little more than 8 points higher than do men.
		If we have a region variable with four categories (Northeast, Midwest, South, and West), we can create up to three dummy variables (such as Northeast, South, and West) in which a case is coded 1 if it is located in the region, and 0 if it is not.
		Note that dummy variables cannot be used as dependent variables in a regression equation.
	www.csupomona.edu /~jlkorey/POWERMUTT/Topics/regression.html (3362 words)

	Variable Selection with Dummy Variables (Site not responding. Last check: 2007-08-19)
		Estimate the full model and examine the dummy variable coefficients for sensible groupings of similar coefficients that might be combined.
		However, with standard variable selection using dummies, there is only one way that categories that can be combined; specifically, all excluded dummies define a the single combined category, and all included dummies represent non-combined categories.
		To select the other variables in a model that has dummies for particular qualitative variable, force all dummies for the qualitative variable to be in every model you consider (use the INCLUDE= option in the proc reg model statement).
	www2.tltc.ttu.edu /Westfall/images/5349/variable_selection_with_dummy_va.htm (391 words)

	Linear Regression Models for Panel Data Using SAS, STATA, LIMDEP, and SPSS
		A dummy variable is a binary variable that is coded either 1 or zero.
		The dummy variable d1 is set to 1 for equipment and software firms and zero for telecommunication and electronics.
		The coefficient of the dummy included means how far its parameter estimate is away from the reference point or baseline (i.e., the intercept).
	www.indiana.edu /~statmath/stat/all/panel/panel2.html (1279 words)

Try your search on: Qwika (all wikis)