Error in solve.default(crossprod(WX, t(crossprod(WX, A1)))) : Lapack routine dgesv: system is exactly singular: U[9,9] = 0, plm package.

Hi guys

Im trying to run a GMM regresson an a larger panel-data set (first 50 rows of data are below). I use the plm package (pgmm). I would like to run the following code for the regression:

gmmCKaopen <- pgmm(log(GDP) ~ lag(log(GDP), 1:1)+lag(ckaopen, 1:1) + diff(Initial.Income, 1:1) + diff(Government.consumption, 1:1)
|lag(log(GDP), 1:1)+lag(ckaopen, 1:1)
data = PData_G_Ckaopen,
effect = "twoways",
model = "twosteps",
)

The following error always occurs:

[Error in solve.default(crossprod(WX, t(crossprod(WX, A1)))) : Lapack routine dgesv: system is exactly singular: U[9,9] = 0]

Has anyone an idea what I have to change that I can run this regression properly.

Data:

                                    GDP     ckaopen       Initial.Income       Government.consumption
                Bangladesh-1970  140.00271        NA      140.00271             0.03335270
                Bangladesh-1971  133.55142        NA      133.55142             0.03379600
                Bangladesh-1972   94.38168 -1.757101       94.38168             0.03456111
                Bangladesh-1973  119.55974 -1.757101      119.55974             0.03599019
                Bangladesh-1974  182.01999 -1.757101      182.01999             0.05493962
                Bangladesh-1975  277.57064 -1.081418      277.57064             0.05869221
                Bangladesh-1976  141.19717 -1.757101      141.19717             0.14966388
                Bangladesh-1977  131.37324 -1.757101      131.37324             0.16965896
                Bangladesh-1978  176.03395 -1.757101      176.03395             0.14669737
                Bangladesh-1979  200.76966 -1.757101      200.76966             0.15294278
                Bangladesh-1980  227.75195 -1.757101      227.75195             0.14808303
                Bangladesh-1981  247.64962 -1.757101      247.64962             0.15393747
                Bangladesh-1982  220.71881 -1.757101      220.71881             0.14891361
                Bangladesh-1983  204.41768 -1.757101      204.41768             0.14592518
                Bangladesh-1984  213.99666 -1.757101      213.99666             0.14477026
                Bangladesh-1985  245.45390 -1.757101      245.45390             0.13990422
                Bangladesh-1986  233.65805 -1.757101      233.65805             0.15099858
                Bangladesh-1987  253.97446 -1.757101      253.97446             0.14051959
                Bangladesh-1988  270.69960 -1.757101      270.69960             0.14034747
                Bangladesh-1989  285.82921 -1.757101      285.82921             0.14981908
                Bangladesh-1990  306.26870 -1.757101      306.26870             0.14068563
                Bangladesh-1991  293.16042 -1.757101      293.16042             0.14220999
                Bangladesh-1992  293.64500 -1.081418      293.64500             0.14563771
                Bangladesh-1993  300.55575 -1.081418      300.55575             0.15749161
                Bangladesh-1994  299.53304 -0.031356      299.53304             0.15656552
                Bangladesh-1995  329.42408 -0.031356      329.42408             0.15148772
                Bangladesh-1996  394.71748 -1.081418      394.71748             0.14238423
                Bangladesh-1997  401.49869 -1.081418      401.49869             0.11078252
                Bangladesh-1998  407.42919 -1.081418      407.42919             0.10166239
                Bangladesh-1999  409.54320 -1.081418      409.54320             0.08855877
                Bangladesh-2000  418.06897 -1.081418      418.06897             0.07495249
                Bangladesh-2001  415.03443 -1.081418      415.03443             0.06737542
                Bangladesh-2002  413.08025 -1.081418      413.08025             0.06804951
                Bangladesh-2003  446.31066 -1.081418      446.31066             0.06985673
                Bangladesh-2004  475.29192 -1.081418      475.29192             0.07041883
                Bangladesh-2005  499.46194 -1.081418      499.46194             0.06887637
                Bangladesh-2006  509.64014 -1.081418      509.64014             0.06758896
                Bangladesh-2007  558.05186        NA      558.05186             0.06355464
                Bangladesh-2008  634.98706        NA      634.98706             0.05938854
                Bangladesh-2009  702.26441        NA      702.26441             0.05882421
                Bangladesh-2010  781.15359        NA      781.15359             0.05633162
                Bangladesh-2011  861.75844        NA      861.75844             0.05380724
                Bangladesh-2012  883.10500        NA      883.10500             0.06018874
                Bangladesh-2013  981.83988        NA      981.83988             0.05950897
                Bangladesh-2014 1118.85366        NA     1118.85366             0.05902864
                Bangladesh-2015 1248.45340        NA     1248.45340             0.05753380
                Bangladesh-2016 1401.62063        NA     1401.62063             0.06004748
                Bangladesh-2017 1563.91370        NA     1563.91370             0.05908680
                Bangladesh-2018 1698.35039        NA     1698.35039             0.06327812
                Bangladesh-2019 1855.73982        NA     1855.73982             0.06525949
                Bangladesh-2020         NA        NA             NA                     NA