For important classes of symmetrically distributed random variables X the smallest constants C[alpha] are computed on the right-hand side of Chebyshev's inequality P(X[greater-or-equal, slanted]t)[less-than-or-equals, slant]C[alpha]EX[alpha]/t[alpha]. For example if the distribution of X is a...

The asymptotic independence and exponentiality of 'pure head run' stopping times will be proved.

The power of the convexity method is demonstrated by proving Qi and Diaz-Metcalf type inequalities.

In a string of n independent coin tosses we consider the difference between the lengths of the longest blocks of consecutive heads resp. tails. We prove that this quantity has an a.s. logarithmic limit distribution as n -- [infinity], though it does not converge in distribution in the ordinary...

This paper studies the competition between firms for influencers in a network. Firms spend effort to convince influencers to recommend their products. The analysis identifies the offensive and defensive roles of spending on influencers. The value of an influencer only depends on the in-degree...

Contextual advertising entails the display of relevant ads based on the content that consumers view, exploiting the potential that consumers' content preferences are indicative of their product preferences. This paper studies the strategic aspects of such advertising, considering an intermediary...

We develop a spreading activation model, which we call the category activation model, to predict where within a category structure consumers are likely to position a subcategory that they have created to accommodate a new hybrid product. Based on this model, we hypothesize that the probability...

The Internet has increased the flexibility of retailers, allowing them to operate an online arm in addition to their physical stores. The online channel offers potential benefits in selling to customer segments that value the convenience of online shopping, but it also raises new challenges....

Web sites invest significant resources in trying to influence their visibility in online search results. We study the economic incentives of Web sites to invest in this process known as search engine optimization. We focus on methods that improve sites' ranking among the search results without...

Paid placements on search engines reached sales of nearly $11 billion in the United States last year and represent the most rapidly growing form of online advertising today. In its classic form, a search engine sets up an auction for each search word in which competing websites bid for their...