NY's decline pretty much bottomed out in the mid- to late 1970s. Koch pretty much put down the groundwork to re-build the city into what it's becoming. That included, solidifying relationships with financial community, real estate folks and media conglomerates.
So, during the later period in the Koch administration you see the rapid decline of manufacturing in NYC, closing of SROs, and all kinds of deals surrounding Times Sq. A lot of tearing down, a lot of debrise. The middleclass is pretty effectively swept out of the city, more homeless on the streets, etc. etc.
I'd tend to agree but then add that it got much worse during the 80's, eventually completely 'bottoming out' during the Dinkins era ('89 to '93) ... the guy (Dinkins) just simply didn't have a grip on anything of any consequence of any kind, in effect he was ineffective and weak ... (but he loved his Tennis games!) ...
The time was ripe for a tough guy like Rudy to come in and clean things up ... which he did, not totally, but effectively ...
So I guess what I'm saying here, (to go back to our original thread exchange), is to give Rudy some credit for being a real NYC guy and a real NYC Mayor