It should be
varname=char('Interest Rate (r)','Investment (i)','Tobin''Q (pk)',...
'Capital (k)','Inflation (\pi)','Wage (w)','Consumption (c)',...
'Output (y)','Labour (l)','Capital Utilisation (mpk)',...
'Premium (pm)','Real cost of Credit (rk)',...
'Networth (n)','M0','M2','Unemployment (u)');
for i=1:15
subplot(4,4,i)
plot(randn(10,1),'r--','LineWidth',1.5)
axis tight;
set(gca,'FontSize',12, 'FontName','Times')
ax = gca;
ax.YAxis.Exponent=0;
title(deblank(varname(i,:)));
end