There's been a lot of hoopla recently about so-called high frequency restaurant reservation trading. Are computers stealing my reservations? Will I ever get into Per Se again? It's Saturday night, I have a hot date but no table, am I screwed?

Last Wednesday, I launched Last Minute Eatin', a same day reservation service that tweets New York's hottest tables. While the service has only been running publicly for a couple of days now, I've been running it silently for quite some time, and it's been monitoring thousands of restaurants for several months now.

It's been rainy here in NYC as of late. Just about the only thing worse than 90 degree city heat is 90 degree city heat with intense thunderstorms roaring through. So I find myself indoors when it rains, crunching data, writing code, checking into GitHub.

Of course I'm not unique here. There are thousands of other GitHub coders in New York and millions of contributors worldwide. The data scientist inside of me asks questions. Is it possible to measure these effects? And if so, exactly how much more do people code when it's rainy?

Dan McKinley recently put together a very useful tool in estimating how long to run your A/B tests.

The obvious corollary here being, “your experiments will take much longer than you think”.

Let’s dive into some real-world numbers.

If you eat out in New York City, the image above should evoke some sort of visceral reaction. In July of 2010, the NYC Department of Health began rating each of the  24,000 restaurants throughout the five boroughs of the city. Each restaurant is given a grade of "A", "B", or "C" based on violations ranging from improper food temperature to sewage problems to the presence of vermin. You can browse  the complete list here.

Fast forward 2 years, and the new system seems to be a win for consumers - Mayor Bloomberg credits the program to a 14% reduction in Salmonella, the lowest rate in 20 years. And according to this press release, NYC restaurant revenue is also up 9.3% since grading began. But still many restauranteurs disagree, expressing anger over these health inspections. Restaurants complain about the complexity in understanding the grading system, fighting with the city over infraction points, and spending additional money to maintain their facilities to meet the city's guidelines.

The Wall Street Journal recently had a piece on investing in the Facebook IPO. They admit, “most retail investors will be shut out of the offering and won't get the IPO price, meaning they likely will have to pay more in the days that follow if they want an early piece of the action”.

To see what’s going on here, let’s take a closer look at what happens on the day of the IPO. In pricing the IPO, there are two prices to consider: the offer price, and the open price. The offer price is set by the company and underwriters. This is the stock price that the company receives in its IPO sale. The open price is set by the publicly traded market on the day the company goes public.