On the accessibility of core-extensions

Sengupta and Sengupta (1996) study the accessibility of the core of a TU game and show that the core, if non-empty, can be reached from any non-core allocation via a finite sequence of successive blocks. This paper complements the result by showing that when the core is empty, a number of non-empty core-extensions, including the least core and the weak least core (Maschler et al., 1979), the positive core (Orshan and Sudhölter, 2001) and the extended core (Bejan and Gómez, 2009), are accessible in a strong sense, namely each allocation in each of the foregoing core-extensions can be reached from any allocation through a finite sequence of successive blocks.