I have undertaken a literature search through 31 July 1997 of white dwarfs ( WDs ) in open and globular clusters .
I have tried to make a careful evaluation in each case of the likelihood that the object is a white dwarf and that it is a cluster member .
The results are presented for 13 open clusters and 11 globular clusters .
Currently there are 36 single WDs and 5 WDs in binaries known among the open clusters , and 340 single WDs and 11 WDs in binaries known among the globular clusters .
From these data I have calculated WD mass fractions for four open clusters ( the Pleiades , NGC 2168 , NGC 3532 , and the Hyades ) and one globular cluster ( NGC 6121 ) .
I develop a simple model of cluster evolution that incorporates stellar evolution but not dynamical evolution to interpret the WD mass fractions .
I augment the results of my simple model by turning to sophisticated N-body simulations incorporating stellar evolution ( Terlevich 1987 ; de la Feunte Marcos 1996 ; Vesperini & Heggie 1997 ) .
I find that even though these clusters undergo a range of degrees of kinematical evolution from moderate ( the Pleiades , NGC 2168 , and NGC 3532 ) to strong ( the Hyades and NGC 6121 ) the WD mass fraction is relatively insensitive to kinematical evolution and little changed from a model incorporating only stellar evolution with a Salpeter-like initial mass function .
By comparing the cluster mass functions to that of the Galactic disk , and incorporating plausibility arguments for the mass function of the Galactic halo , I estimate the WD mass fraction in these two field populations .
I assume the Galactic disk is \sim 10 Gyrs old ( Winget et al . 1987 ; Liebert , Dahn , & Monet 1988 ; Oswalt et al . 1996 ) and that the Galactic halo is \sim 12 Gyrs old ( Reid 1997b ; Gratton et al . 1997 ; Chaboyer et al . 1998 ) , although the WD mass fraction is insensitive to age within this regime .
I find that the Galactic halo should contain from 8 to 9 % ( \alpha = -2.35 ) or perhaps as much as 15 to 17 % ( \alpha = -2.0 ) of its stellar mass in the form of WDs .
The Galactic disk WD mass fraction should be 6 to 7 % ( for a median stellar age of 5 to 7 Gyrs and \alpha = -2.35 ) , consistent with the empirical estimates of 3 to 7 % ( Liebert , Dahn , & Monet 1988 ; Oswalt et al . 1996 ) .