Analisis pengaruh struktur persaingan pasar dan perubahan tingkat suku bunga terhadap jumlah tabungan PT. Bank Rakyat Indonesia, Tbk Periode 2006-2007 dari sudut pandang pendekatan Structure-Conduct-Performance = Analysis of the effect of market competition structure and interest rate changes on total savings in PT Bank Rakyat Indonesia, Tbk Period 2006-2007 from the view of structure- Conduct-Performance Approach