Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A statistical analysis of product prices in online markets   We empirically investigate fluctuations in product prices in online markets
by using a tick-by-tick price data collected from a Japanese price comparison
site, and find some similarities and differences between product and asset
prices. The average price of a product across e-retailers behaves almost like a
random walk, although the probability of price increase/decrease is higher
conditional on the multiple events of price increase/decrease. This is quite
similar to the property reported by previous studies about asset prices.
However, we fail to find a long memory property in the volatility of product
price changes. Also, we find that the price change distribution for product
prices is close to an exponential distribution, rather than a power law
distribution. These two findings are in a sharp contrast with the previous
results regarding asset prices. We propose an interpretation that these
differences may stem from the absence of speculative activities in product
markets; namely, e-retailers seldom repeat buy and sell of a product, unlike
traders in asset markets.

16
The categories of this paper are: stat
30
The categories of this paper are: q-alg
10
The categories of this paper are: q-bio
7
The categories of this paper are: hep-th
13
The categories of this paper are: quant-ph
23
The categories of this paper are: solv-int
17
The categories of this paper are: q-fin
2
The categories of this paper are: math
29
The categories of this paper are: funct-an
1
The categories of this paper are: cs
24
The categories of this paper are: dg-ga
6
The categories of this paper are: astro-ph
31
The categories of this paper are: ao-sci
12
The categories of this paper are: nucl-th
14
The categories of this paper are: math-ph
0
The categories of this paper are: hep-ph