Describe Perez's model of technological, financial and institutional systems coevolution. What does Perez mean by the terms (a)'irruption' and (b) 'turning point'? Discuss the roles of the principal agencies (individuals, firms, institutions, government, etc.) driving or being influenced by change during (a) an 'irruption' and (b) a 'turning point'? Illustrate your answer with a straightforward case example.