Cabot is a global specialty chemicals and performance materials company headquartered in Boston, Massachusetts. Our principal products are rubber and specialty grade carbon blacks, specialty compounds, fumed metal oxides, activated carbons, inkjet colorants, aerogel, cesium formate drilling fluids, and fine cesium chemicals. Cabot and its affiliates have manufacturing facilities and operations in the United States (“U.S.”) and over 20 other countries. Cabot’s business was founded in 1882 and incorporated in the State of Delaware in 1960. The terms “Cabot”, “Company”, “we”, and “our” as used in this report refer to Cabot Corporation and its consolidated subsidiaries.
Our vision is to be the most innovative, respected and responsible leader in our markets – delivering performance that makes a difference. Our strategy is to extend our leadership in performance materials by investing for growth in our core businesses, driving application innovation with our customers, and generating strong cash flows through efficiency and optimization. Our products are generally based on technical expertise and innovation in one or more of our four core competencies: making and handling very fine particles; modifying the surfaces of very fine particles to alter their functionality; designing particles to impart specific properties to a formulation; and combining particles with other ingredients to deliver a formulated performance intermediate or composite. We focus on creating particles, and formulations of those particles, with the composition, morphology, and surface functionalities to deliver the requisite performance to support our customers’ existing and emerging applications.
Our four business segments are: Reinforcement Materials; Performance Chemicals; Purification Solutions; and Specialty Fluids. The business segments are discussed in more detail later in this section. Financial information about our business segments appears in “Management’s Discussion and Analysis of Financial Condition and Results of Operations” in Item 7 below (“MD&A”) and in Note S of our Notes to the Consolidated Financial Statements in Item 8 below (“Note S”).
Our internet address is www.cabotcorp.com. We make available free of charge on or through our website our annual reports on Form 10‐K, quarterly reports on Form 10‐Q, current reports on Form 8‐K, and amendments to those reports filed or furnished pursuant to Section 13(a) or 15(d) of the Securities Exchange Act of 1934 as soon as reasonably practicable after electronically filing such material with, or furnishing it to, the SEC. Information appearing on our website is not a part of, and is not incorporated in, this Annual Report on Form 10‐K.
On page 42 of the 2017 Annual report, following information is provided. 

Inventory Valuation
The cost of all carbon black inventories in the U.S. is determined using the last‐in, first‐out (“LIFO”) method.
Total U.S. inventories utilizing this cost flow assumption were $28 million at both September 30, 2017 and 2016.
These inventories represent 7% (342 million) and 8% (396 million) of total worldwide inventories at September 30, 2017 and 2016, respectively. Had we used the first‐in, first‐out (“FIFO”) method instead of the LIFO method for such inventories, the value of those inventories would have been $37 million and $27 million higher as of September 30, 2017 and 2016, respectively. The cost of Specialty Fluids inventories that are classified as assets held for rent is determined using the average cost method. The cost of other U.S. and all non‐U.S. inventories is determined using the FIFO method. In periods of rapidly rising or declining raw material costs, the inventory method we employ can have a significant impact on our profitability. Under our current LIFO method, when raw material costs are rising, our most recent higher priced purchases are the first to be charged to Cost of sales. If, however, we were using a FIFO method, our purchases from earlier periods, which were at lower prices, would instead be the first charged to Cost of sales. The opposite result could occur during a period of rapid decline in raw material costs.


Based on the above
1. Did the inventory of carbon black increase or decrease?