Editing Business cycle (section)

== Software ==
The Hodrick-Prescott<ref name="HP">{{cite journal |last1=Hodrick |first1=R. |last2=Prescott |first2=E. |year=1997 |title=Postwar US business cycles: An empirical investigation |url=https://www.jstor.org/stable/2953682 |journal=Journal of Money, Credit and Banking |volume=29 |issue=1 |pages=1–16 |doi=10.2307/2953682 |jstor=2953682 |s2cid=154995815}}</ref> and the Christiano-Fitzgerald<ref name="CF">{{cite journal |last1=Christiano |first1=L. |last2=Fitzgerald |first2=T. |year=2017 |title=The band-pass filter |url=https://onlinelibrary.wiley.com/doi/abs/10.1111/1468-2354.t01-1-00076 |journal=International Economic Review |volume=44 |issue=2 |pages=435–465 |doi=10.1111/1468-2354.t01-1-00076}}</ref> filters can be implemented using the R package 
[https://cran.r-project.org/web/packages/mFilter/index.html mFilter], while singular spectrum filters<ref name="dC2017">{{cite journal |last1=de Carvalho |first1=M. |last2=Rua |first2=A. |year=2017 |title=Real-time nowcasting the US output gap: Singular spectrum analysis at work |url=https://www.sciencedirect.com/science/article/abs/pii/S0169207015001247 |journal=International Journal of Forecasting |volume=33 |pages=185–198 |doi=10.1016/j.ijforecast.2015.09.004 |s2cid=44189755}}</ref><ref name="dC2012">{{cite journal |last1=de Carvalho |first1=M. |last2=Rodrigues |first2=P. C. |last3=Rua |first3=A. |year=2012 |title=Real-time nowcasting the US output gap: Singular spectrum analysis at work |url=https://www.sciencedirect.com/science/article/abs/pii/S0165176511003363 |journal=Economics Letters |volume=114 |pages=32‒35 |doi=10.1016/j.ijforecast.2015.09.004 |s2cid=44189755}}</ref> 
can be implemented using the R package [https://cran.r-project.org/web/packages/ASSA/index.html ASSA].