Last I checked there was a Tokyo , Hongkong, London Chicago etc exchange. All causing Wallstreet would do is shift the trade out of NYS. NYS, as you know, has lost , even before recession, many many Mfg. jobs. NYS is butt deep in debt. NYS is millions and millions SHORT in the income tax area because of this recession. Closing would break NYS , my home would be WORTHLESS, as would millions of others. The state would IMPLODE as would the nations ecomony, making the current recession look like a baby's burp.
Worse yet, another market would open somewhere else, and THEY'D become vastly wealthy on the stock trade. Capital will ALWAYS go here it is welcomed and leave where it is abused. As would anyone with any sense whatever.