On the Fay identity for KdV tau functions and the identity for the Wronskian of squared solutions of Sturm-Liouville equation

We show that the well known identity for the Wronskian of squared solutions of a Sturm-Liouville equation follows from the Fay identity. We also study some odd-order (($2^n -1$)-order, $n = 2, 3, ...$) identities which are specific for tau functions, related to the KdV hierarchy.Comment: Amstex, 13 page

Decision making pattern of subsistence farmers in Bulgaria

Economic research by and large is dominated by a ‘rationality’ paradigm. Economic decision making within this paradigm is viewed as a maximising procedure. In general the latter represents the decision-making as a choice amongst a well defined set of alternatives. In this paper we question this and analyse the options of the small-scale subsistence farmers in Bulgaria in the way they see them. By applying mental accounting methodology we deduce some significant characteristics of Bulgarian subsistence agriculture.