depending on departure time, demand, and the time the ticket is booked. Skiing Yield Management has shown increasing popularity in the ski industry, especially in the North American markets. This ranges from non-physical rate fences, including age and validity differentiation to fully dynamic prices. Determinants of such variable prices include date-specific expected demand factors (institutional and public holidays, weekends, weather, size and accessibility of the resort, etc.) Pet Boarding With predictable demand far outnumbering fixed supply in the professional pet boarding industry, Yield Management has become an ever-popular practice for this segment of businesses. Much like the hotel industry, these systems help gauge which restrictions to implement, e.g. length of stay, non-refundable rate, or close to arrival, while also ensuring they are selling rooms and services at the right price, to the right person, at the right time. Econometrics Yield management and econometrics center on detailed forecasting and mathematical optimization of marginal revenue opportunities. The opportunities arise from segmentation of consumer willingness to pay. If the market for a particular good follows the simple straight line Price/Demand relationship illustrated below, a single fixed price of $50 there is enough demand to sell 50 units of inventory. This results in $2500 in revenues. However the same Price/Demand relationship yields $4000 if consumers are presented with multiple prices. In practice, the segmentation approach relies on adequate fences between consumers so that everyone doesn't buy at the lowest price offered. The airlines use time of purchase to create this segmentation, with later booking customers paying the higher fares. The fashion industry uses time in the opposite direction, discounting later in the selling season once the item is out of fashion or inappropriate for the time of year. Other approaches to fences involve attributes that create substantial value to the consumer at little or no cost to the seller. A backstage pass at a concert is a good example of this. Initially yield management avoided the complexity caused by the interaction of absolute price and price position by using surrogates for price such as booking class. By the mid-1990s, most implementation incorporated some measures of price elasticity. The airlines were exceptional in this case, preferring to focus on more detailed segmentation by implementing O&D (Origin & Destination) systems. At the heart of yield management decision-making process is the trade-off of marginal yields from segments that are competing for the same inventory. In capacity-constrained cases,