Hey Peter, thank you. Yes, I want to have "year" in the varibale. But if I use "*town*year*" as a furmula, R will create new factor variable with n levels, where n = (num of towns) x (num of years). What I'm trying to do is create 50 (town x year) variables such that town1xyear is 1,2,3... when town== 1 and zero otherwise, repeat for town2xyear, where state == 2, etc.
It is now clear? Sorry for my bad explanations. Toby Am 12.05.2017 um 23:23 schrieb peter dalgaard: >> On 12 May 2017, at 16:40 , Tobias Christoph <s3toc...@uni-bayreuth.de> wrote: >> >> Hey guys, >> >> thanks a lot for your tips. The regression is finally running. As you >> said, I had to integrate the column "year" in the function "time" in R. >> >> So I used the following formula: *plm(log(revenue) ~ log(supply) + >> factor(town)*time(year), data=R_Test_log_Neu)* > Um, that might not do what I think you think it does. time() gives you the > "vector of times at which a time series was sampled". If you feed it any > regular vector, it just gives the numbers 1:n, witness > >> time(rnorm(20)) > [1] 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 > attr(,"tsp") > [1] 1 20 1 > > I suspect you just want "year" in the formula. > >> So I have now sucessfully added a linear trend to my regression model? >> Another question that concernes me is how to add a quadratic trend >> instead of a linear trend. Can I just square the column "year"? > In principle, yes, but as others have pointed out, centering the variable may > be a good idea, for numerical stability. > > -pd > >> Enjoy your weekend, >> >> Toby >> >> _My results see below:_ >> >> Balanced Panel: n=11, T=12, N=132 >> >> Residuals : >> Min. 1st Qu. Median 3rd Qu. Max. >> -0.09610 -0.02370 -0.00152 0.01980 0.14000 >> >> Coefficients : >> Estimate Std. Error t-value Pr(>|t|) >> log(supply) -0.0080702 0.0133675 -0.6037 0.547411 >> factor(town)2:time(year) -0.0063245 0.0053744 -1.1768 0.242100 >> factor(town)3:time(year) 0.0295522 0.0056776 5.2050 1.053e-06 *** >> factor(town)4:time(year) 0.0062191 0.0054152 1.1485 0.253549 >> factor(town)5:time(year) 0.0159028 0.0054954 2.8939 0.004681 ** >> factor(town)6:time(year) 0.0237112 0.0055395 4.2804 4.316e-05 *** >> factor(town)7:time(year) 0.0410007 0.0055734 7.3565 5.576e-11 *** >> factor(town)8:time(year) 0.0239085 0.0053751 4.4480 2.271e-05 *** >> factor(town)9:time(year) 0.0242342 0.0056855 4.2625 4.619e-05 *** >> factor(town)10:time(year) 0.0105890 0.0053302 1.9866 0.049733 * >> factor(town)11:time(year) 0.0095270 0.0056354 1.6906 0.094065 . >> --- >> Signif. codes: 0 �***� 0.001 �**� 0.01 �*� 0.05 �.� 0.1 � � 1 >> >> Total Sum of Squares: 0.46388 >> Residual Sum of Squares: 0.2001 >> R-Squared: 0.56863 >> Adj. R-Squared: 0.4292 >> F-statistic: 11.8637 on 11 and 99 DF, p-value: 7.3065e-14 >> >> >> >> Am 11.05.2017 um 23:17 schrieb David L Carlson: >>> What Rui said, but as important, you have four columns in your data called >>> "town", "year", "revenue", and "supply". You do not have a column called >>> "time". >>> >>> ------------------------------------- >>> David L Carlson >>> Department of Anthropology >>> Texas A&M University >>> College Station, TX 77840-4352 >>> >>> -----Original Message----- >>> From: R-help [mailto:r-help-boun...@r-project.org] On Behalf Of Rui Barradas >>> Sent: Thursday, May 11, 2017 3:36 PM >>> To: Tobias Christoph <s3toc...@uni-bayreuth.de>; Duncan Murdoch >>> <murdoch.dun...@gmail.com>; r-help@r-project.org >>> Subject: Re: [R] Error: invalid type (closure) for the variable 'time' - >>> object specific trend >>> >>> Hello, >>> >>> A closure is, like you say, a function. >>> At an R prompt try: >>> >>>> typeof(time) >>> [1] "closure" >>> >>> So like Duncan suggested rename 'time', for instance capitalize it >>> 'Time'. That should do it. >>> >>> Hope this helps, >>> >>> Rui Barradas >>> >>> >>> >>> Em 11-05-2017 21:20, Tobias Christoph escreveu: >>>> Hey Duncan, >>>> >>>> thank you very much for your quick reply. >>>> >>>> _My data used:_ >>>> >>>> 1st column(town):1,1,1,1,1,1,1,1,1,1,1,1,2,2,2,...........,11 >>>> >>>> 2nd column(year):1,2,3,4,5,6,7,8,9,10,11,12,1,2,3.......,12 >>>> >>>> 3rd column (revenue): >>>> >>>> 4th colum (supply): >>>> >>>> I have now renamed my colums and did the regression again. Now there is >>>> a problem with R-squared, as it is the sum of 1 now with no given std. >>>> error and t-value. This is probably due to the fact, that I try to >>>> estimate more parameters than data. >>>> >>>> To add a linear trend I found the following formular:*lm(y ~ x1 + >>>> factor(ccode)*time, data=df)* >>>> >>>> I try to I decode it for and use it for my regression: *plm(log(revenue) >>>> ~ log(supply) + factor(town)*time, data=R_Test_log_Neu)* >>>> >>>> When I do this regression I will get the original error: "invalid type >>>> (closure) for the variable 'time' - object specific trend" >>>> >>>> With the notation"time" not my colum is meant, but probably the command >>>> "time" in R. >>>> >>>> Can you follow my thoughts? >>>> >>>> Tobi >>>> >>>> >>>> >>>> >>>> >>>> >>>> Am 11.05.2017 um 17:23 schrieb Duncan Murdoch: >>>>> Duncan Murdoch >>>> ______________________________________________ >>>> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see >>>> https://stat.ethz.ch/mailman/listinfo/r-help >>>> PLEASE do read the posting guide >>>> http://www.R-project.org/posting-guide.html >>>> and provide commented, minimal, self-contained, reproducible code. >>> ______________________________________________ >>> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see >>> https://stat.ethz.ch/mailman/listinfo/r-help >>> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html >>> and provide commented, minimal, self-contained, reproducible code. >>> >> >> [[alternative HTML version deleted]] >> >> ______________________________________________ >> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see >> https://stat.ethz.ch/mailman/listinfo/r-help >> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html >> and provide commented, minimal, self-contained, reproducible code. [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
